Try this site, conversion pieces for small and medium tenders.
http://yardbirdtrains.com/index.htm
Here is a direct link.
http://www.yardbirdtrains.com/YBDetailParts.htm
I have the kit for a slope back tender.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.