Stripped it down today, going to have to replace the stem bolts and seat clamp bolt with some nice stainless ones as they're corroded and chewed. Also unfortuantely one one of the Cantilevers has been overtightened and cracked, not sure if it can be repaired so may have to try and find a replacement for that too. Otherwise all is good and just needs a good clean up and a bit of grease. No serial number on the BB shell, just the one on the dropout. Defintately convinced this is a 1995 USA Speed Series PRO XXL from comments here, the serial number and my own research.