Hey C&V, I have a real quick question. I'm rebuilding an old townie with my g/f as her first bike project, and i need to replace the rusted 5-speed Mallard freewheel (one i find a tool to remove it!). I have a spare 6 speed Shimano MF-Z012 freewheel I'm hoping I can use. Will this freewheel work with her Sachs Huret Eco rear derailer? All shifting is friction.

Thanks