Fox Collectors

I am speaking about a Fox B trip and spring possibly being the right size for a Sterlingworth. Has anyone tried that route?

I have a 12ga Sterlingworth from around mid-30's that needs a trip and spring. Any chance the Savage Foxes use the same part? The person who worked on the gun coated the receiver with a shellac, so before I crack the seal on the bottom action screw, I want to know a bit more.