I must say I was assuming an un-extended car shape as per Zagato-Olaf's photographs as I too have no photographs of the car in period and, personally, the normal body shape is still visually the best. I am, of course, aware that certain GRP panels were homologated at differing times for the Junior but clearly at some time it didn't have them.
Perhaps further research is needed to find what precise specification the car had at the date at which the replica is being "realistic"! Period racing photographs would clearly show if the body were extended but would not show if the roof, bonnet and doors were GRP. Are you to re-produce the car's precise livery too?
Alternatively you can throw "realism" out of the window and say "I will have the wide body, GRP everything........ because that's what I like" and have fun!
