Although the Mark 5/V poly-v belt is narrower than the original Mark VII poly-v belt, it WILL work. Bandsaw Tire Warehouse has a belt made to Mark VII specs(wider) available on E-bay.
The motor belt is NOT the same as a Mark V/5 motor belt. However it is a 1/2" standard v-belt which I believe to be 30 1/2" long. I recommend a 'cogged' automotive belt. Since belts today are typically slightly narrower than the original belt the speed range is moved slightly upward.
Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10E(SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange