I see I wrote about the pressed on end gear on the main shaft. I forgot to add that it has to be pressed up to have running clearance plus a fraction. If you keep pressing it'll lock the gear it comes up to. By memory I used to get it close with a feeler gauge in there then bang the press somehow while keeping pressure on to get it to creep that last little bit & bite the feeler blade lightly. Otherwise you can guarantee one more normal press pump & it'll go 'too far' & lock up. Stop too short & leave a lot of end clearance would mean less engagement of the sliding gear which by memory makes 5th gear when engaged. That sounds complicated now I've written it, sorry about that.

Please don't apologize. I can use all the info I can get. Thanks so much.