Thanks Jessica,
One speed build coming up. Actually, I'd browsed this thread a few times but didn't realise just how old the Airfix Gosling kit was, being in a new box etc.
Anyway, build started...
Oh dear, big mismatch here:

Added a 1mm shim between the engine sides and looking better now.
Canopy stuck out about a mm on each side so attacked it with the raspy stuff. The culprits:

Looks like nothing will ever be seen through here again:

But, after a good polish and a coat of New Klear:

It's not brilliant (still slight scratches) but more than good enough in 1/72. The gloss and clarity entirely depends on the amount of work put into the polishing.
Fit issues on all the windows:


Getting there...
Drat, I haven't got any Dark Slate Grey paint!