As I've been accumulating more data in my quest to add more (and, eventually, hopefully every) variant of panel to the list of reproduction panels I can make for Marshall restorations, I've learned a lot. I'm going to share some of my findings with you because you might be interested to know, particularly if you are interested in restoring your old Marshall or even just trying to replace a badly damaged or missing panel for it. There are far more variations on the panel types than I ever imagined. I'm getting close to 50 patterns and I know I'm not done yet. Let's look at just a single family of panels. That'd be the JMP 100 watt rear panel for the Super Lead 1959 type, and, later, the 2203 Master Volume type. For one thing, I have realized that the original panels were screen printed in at least two separate stages. All of them share the "Made in England by Jim Marshall Products" legend, and those common printed features that apply to all 100 watters. Screening for the speaker icon, mains legend, fuse legends (where it's not dymo tape), and of course, the impedance selector legend. It appears that this was the common silkscreen for almost every 100 watt JMP made from 1973 onward until maybe 1979. The other legends, such as the block printed SUPER LEAD 100w or SUPER BASS 100w or SUPER TREMOLO 100w were all printed in a secondary process, and I say this because the common printed features I described earlier never change at all. They're always the same down to tiny details. Plus, the Super Lead and Super Bass and Super Tremolo screening was all over the place. I've seen some that were printed half an inch higher up the panel than others. If you look at a lot of old JMPs you'll see this very quickly. The screening for the voltage selector also appears to have been applied in a separate process, for those amps that were equipped with it. There are a fair number of optional ways to make the original panels and I mirror those changes with what I offer. Number of speaker jacks can be two or four. The mains voltage selector markings and punched hole can be deleted or added. IEC sockets were never standard on a JMP era 100 watter so I don't offer an IEC punchout because if your amp has it, it was installed by a technician and the installation has no standardized format. The options I provide for power input are Bulgin socket punchouts or grommeted, permanently attached line cord using a Heyco 5/8" OD double flatted D grommet. Those things alone require me to offer not less than eight different metalwork punch patterns for the 100 watt rear panels alone, for Super Bass and Super Lead rear panels, and not less than sixteen different variations on the artwork. (All the previously listed punch options plus I have to duplicate them for both Super Lead and Super Bass marked units.) The 1959T Super Tremolo unit is a special case. Although similar I don't classify it as a 1959 panel due to its differences. It's a 1959T panel and is its own thing. (I need to update my files to reflect that. I'm offering a Super Tremolo panel that actually shouldn't exist but it can work if you have just two speaker jacks and deleted the tremolo footswitch socket.) Going by the reference information available at amparchives.com, it appears that they didn't make them past 1971. The 1959T chassis punch pattern has a footswitch punch in the middle of the four possible speaker jacks, which if equipped, gives two speaker jacks on the left, and two on the right, of the footswitch jack. Some are equipped with all four jacks, others are not. The 1959 Super Lead used the rear chassis hole punch pattern of the 1959T Super Tremolo in those years where both models were available. It wasn't until the 1959T was discontinued that Marshall changed the chassis pattern to delete the unnecessary punched holes that would no longer be needed. I have not seen a 1972 chassis that was based on the 1959T chassis pattern so I assume that Marshall used up all the T chassis in 1971. The really strange thing about that is that while the 1959T and 1959 chassis shared the same back panel punch patterns from 1967 to 1971, the front of chassis hole punch pattern was always unique to the model. You don't see a 1959 that was actually built in a full spec 1959T chassis punched for eight front panel controls plus indicator and switches. But despite that, the Superlead 1959 chassis does have the extra punch for a fourth preamp tube socket (for the tremolo) for every year from 1967 to 1971. Marshall was consistent in one thing: Their inconsistency! Some rear panels have small dots printed on them. These are alignment dots so that the panel could be placed correctly for the sheet metal shop to punch the holes out more or less properly aligned to the artwork. The artwork was silkscreened first, punching came later. I have so far only seen those dots on amps that were made no later than 1974. I don't understand the specifics of when they were printed with dots outside of that. Nor do I know how consistently they were used during that time period. Even the presence, or absence, of the OUTPUT legend below the speaker jacks (bottom edge under the speaker icon) seems to be almost random for 1959 Superleads. Some have them, some don't. I haven't found the pattern for that yet. Apparently, MARK II appeared on the rear 1959 and 1987 panels in 1974. It seems that it should not be present prior to 1974 but I'm still looking to confirm that. I'll stop now. I'm getting pedantic the way I always do when seeking information. But you can see for yourself that by the time I've got most of the models figured out, I'm going to be a subject matter expert-in-training on Marshall front and rear panels! I'm starting to think Marshall never made more than 100 amps or so before they changed something!