I could use the pedals, that is the last piece of the puzzle for my grandpas old number 5
View attachment 320785
Measure that No. 5 for applicability.
My No. 5 (three pedal velocipede) is 31" between the inside of the legs. Yours appears as if it may be a 4 pedal velocipede.
So you may want to confirm fit.
Both 4-1/2 and 5 were made in "extended bed" versions.
If yours is indeed the "longer" No. 5, then your best chance may be to have a replacement velocipede pedal shaft made.
My No. 4-1/2 has the replacement pedal shaft. This was sold to me as a unit (shaft, pedals, hangers & bearings) for $180 now about 10 years ago. The reproducer of this particular part (initials DC) is now out of the hobby, but the torch has been passed to another, who may contact you.
The replacement pedal shaft actually is slightly "improved" over the originals as the original were 11/16 where the gear fits, the new ones are 3/4". The remainder of the pedal shaft is identical (and fits the triangle pedals.)
Whoever made my 2 pedal shaft (4-1/2) can make it larger, and probably has.
Joe in NH