Hello folks, Just acquired a 2034 cabinet, which I believe is a ‘73 according to the cabinets database by Marstran.com gratefully. I have gone through all threads that mention “7442” speakers. Mine has 7442U stamped on all speakers, which are on black baskets with 8401 stamped on cones. Can I please get an education on source of these speakers and what disability the U or the 8401 signify? I would greatly appreciate it.