Thanks for any help I know Yankee models makes a resin one.
Can anyone help
I would either mold curved sections of flat styrene over an appropriate diameter plastic pipe by immersion in boiling water or cut the pieces out of plastic pipe . The styrene will be easier to glue as you are working with the same material as the kit .
The pipe will likely be PVC or ABS . Epoxy may be needed to fasten .
I believe Glenn Cauley had some tips on scratchbuilding one. Think he has a website.
Here is a link to the Glenn Cauley website. Looks like some great info!