if building glass bows the plywood form would have to fit in the box also fiberglass comes in 72 inch lengths, If for self bows then I guess it would depend on stave lengths. When I built mine I had to buy plywood so I made it 78 inches long. I think you would be ok, but you could lay a piece of the 75 in ply on your bench and lay some materials on it to see if it is long enough for you. I built mine for glass bows to the Bingham Projects specs and put castors under it. I built a stand up hot box with a single light bulb and small fan in 1994 for staves and made it 24x24x84, it seemed to work fine for boards,billets and staves.