1936 Sedan sliding roof

Hello, when I got my 2.5 SS Jag saloon back on the road I was delighted that my rebuilt timber and cloth covered sliding roof fitted the hole and lined up nicely with the rear fixed panel. However, the roof will not slide. I can identify several possible reasons; the rear panel does not have enough height; the sliding roof panel may be too thick (although both parts of the roof line up nicely with each other and with the bodywork generally); the brass rails on each side may be misaligned, the slides at front and back corners of the sliding panel may be in the wrong place or misaligned. I’d welcome ideas, and also confirmation from any '36 owners that the original design did actually work!
Chris Lovell-Smith

Chris If you could send me some pics of your set up, I’ll compare it to the 37 car
I’m not sure about " brass rails"