Hi Clive, long time "no talk".
My little Sprite is coming along well, got the body back from the body shop a couple weeks ago, got the doors back today, and a few other odds and ends. Seems like it'll take a year total before I have all the body parts restored. Transmission is apart, I believe I have all the parts required to reassemble it. It's the original "smoothcase" 4 speed.
On the 140 chassis key, just as a cross-reference, the owners manual will have the resynchronization procedure. Steve is probably right, but it seems they did change the procedure occasionally. If Steves way doesn't work, check the manual.