Cab on M37 is narrower and shorter. Top for M35 is therefore a bit large. I do know of a couple of folks who have managed to fit a M35 vinyl top onto a M37, but considering the cost of a good reproduction M37 top versus the cost and effort to fit a comparable M35 top, I'd suggest going with a M37 top...
Both Dave a Weebee Webbing and Judith at New Life will do tops for M37 in custom colors/materials as well as the original canvas and both offer the tops in vinyl as well (not sure about camo patterns though).