Just a thought have just seen an autohomes renault traffic mk1 conversion with the solid sided poptop in the local scappy didnt have a tape to hand what are the chances of the poptop being made to fit a t25 any one had a go?
Without the sizes, who knows? As long as it's shorter and narrower than the T3 (allowing for tha tailgate)then you can trim the fibreglass to the roof contour - with patience and the right disc.
The rest is just blacksmith work. Might look hideous, mind.
1985 Oettinger 3.2 Caravelle RHD syncro twin slider. SA Microbus bumpers, duplex winch system, ARC 7X15 period alloys