looking for a Franklin fitting. number cast in body says F85N.

Ok. I’ll bite. What is it and do you have any photos or at least a description?

Need more info. The interwebs do not have many "old fashioned" parts stored in them for ordering.

A quick search on "Franklin F85N" turns up some sealing rings for hydraulic fittings. Not sure if that is what you need;

https://www.flaretite.com/flaretite-seal

Good luck, Kevin