I don't recall what the serial number range was for switching to the one piece sear spring but your gun likely has the original individual sear springs. There will be a thin slot machined into the frame for the one piece spring to slide into or there will be two individual holes for the early style sear springs legs to sit in.
The link below is a drawn schematic view of a Parker receiver but it's not the most accurate. It does give a good representation of the one piece sear spring, part #39, along with how the frame is machined to hold it.
https://www.bevfitchett.us/firearms-...isassembly.jpg
Threaded Mode