Interesting basses these. I have a very early one- 1980 according to the man- and the shape is actually quite different. The top bout on mine is much more pointy, this one is quite rounded. There is a routered rebate around the top of mine, which has disappeared here, the pickups have moved (on the earlier basses the neck pickup was further towards the erm...neck), they have changed make (from Bill Lawrence blades to the Kent Armstrongs on this one) and the early ones had a passive tone circuit, whereas this one is active. The bridge on mine is a schaller, same as this, so maybe the one with the Overwater branded bridge is a very late one? Or did they change, then change back for some obscure eighties supply related issue? Who knows.....
Anyway, fascinating. You have a lovely looking bass there. Shame these don't attract the same cachet as Wal's, otherwise someone would probably have paid you £240,000,000 for it twelve seconds after you put the advert up. 😂