I can do that now as it is. Even though it's broken, as long as I use the key first (thanks for the tip) it clicks in nicely and will require a serious bit of aggressive behaviour to break it off completely.
I found that loosing the bolt that fixed it removes a lot of the strain on the unit and I can easily just support the lock unit with one finger with the key turned and gently click the seat into place. Works lovely and smoothly now. I'll keep an eye on it and save the 55 pounds for fuel.
If I get it fixed or replaced I'll check out the washers jar for suitably sized ones!
Here's a few crappy iPhone pics I took in my attempts!
A bit out of sequence but you get the idea. Must give the whole area a decent clean before I start next time. Might have been part of my lack of success with the glue. I was hoping it would work for more than one try!
I think it needs support along the broken end. Not the sides... I have not given up. I know there are at least ten reasons I don't need to but some small drill bits and some small self tappers. Must look out for bits to cannibalise from an old phone or a radio or something.
