Thanks guys.
Not so "Spiffing" or "Spiffy" is this issue that I encountered before with the Tamiya Spit Mk I kit. Clearly it's a mold issue that results in the rear canopy glazing being much too wide for the fuselage profile (see circles in the pic below). When I tried to fix this on the Mk II, I ended up breaking the clear part and I heard, I think, that Jason (JayL) broke a canopy part.
So, any bright ideas on how to fix this? It's crossed my mind to drop the part in very hot water and then pinch it to shape while it cools but I'm still worried that I'll bust it. Looking for ideas here, thanks.