Old bike chain advice

[porteous]

I'm rebuilding a 1957 Rudge pathfinder which was originally fitted with a 4 speed cyclo derailleur running on 1/8 chain. The bike came with no wheels but the cyclo mech is still there and I would like to use it but cannot get a 4 speed 1/8 freewheel.

I am wondering whether I could get away with fitting a modern 5 speed cog set and run a 3/32 chain through the cyclo mech? Anyone tried this?

 

[tyred]

I don't see why not. The actual difference in the width of the chain is very slight and these older mechs were never high precision engineering in the first place.