'79 onwards... iirc...?
One of the things that always irked me with mine ('78) were the switch positions, so I moved the pup selector to the Les Paul position and split the single FX to two minis located near the pointed section of the scratch below the bridge pup...
The other thing was the white dot markers which Peter Cook kindly changed over to black when he also ground the frets down so I could experiment as a fretless...
I really should finish my rebuild...
Yeah, mine is a very late '79 model (stamped on 5th Dec).
And yes, you should finish your rebuild, because they're amazing basses. The people who had a go of mine at the weekend were surprised at how easy it was to play, considering they do look like giant, recalcitrant beasts