Cool old bike. seems to me that with a little creativity you could get some Raleigh parts to fit.
Check Sheldon Brown's site for a better idea of tire size. They're out there but the LBS usually doesn't understand anything other than 700s or those old fashioned obsolete really rare 27"s.
These are simple machines. You'll just have to do a little research and thinking.
There are a couple of websites that sell modern chinese bikes and parts (Yellow Jersey or that place that sell pennyfarthing replicas). They might know something.