Well another update, slightly more positive this time - after a days fettling the roof is showing signs of wanting to fit.. but it still needs a LOT of work around the windows, and a fairly substantial amount in a few other places! In the meantime I probably should find out who made the GTN hardtops - could come in useful if my one ends up being a dead end.
I took a few pictures to show the progress, firstly the roof "plonked" in position (soft-top full removed to facilitate this)
Slight gap at the top - lip from the mould needed trimming to get this to fit
Hmmm this could be a tad breezy - even for a Mog!
A large amount of work later and some progress... the front lip has been trimmed to allow it to fit neatly to the screen area, and the rear is fitting flusher to the deck
The window gap is better, but that is better as in you won't fall out of it now
In this pic if you squint and stand back a little it still doesn't fit