I think that all is there for the most part, all you need is a flat piece of wood for yer foot and a piece of heavy guage wire to hook up to the piece that is hanging down from the crank.
There may be some holes in the legs intended to hold a dowel between the legs, but I dunno if that is necessary. The wheel was likely complete, but the foot board got lost in action. I see the holes now in the pix, and they look like they are intended to hold a metal rod rather than a dowel, You could put it to working order with just a piece of wood if you didn't want the fuss, but you might want to put a piece of felt at the heel of the board to avoid damaging yer floor...
Yer also missing the drive belts, but these can be fabicated out of leather lacing , If you dampen them slightly, they can stretch and you can get the dimnsion, cut bevels and stitch them together with waxed heavy duty thread (preferrably linen) and when they dry they will shrink and fit tightly. Get em too wet, they will shrink too much. and possibly be too tight.
An exquisite gift