Hello,
That 180 prefix would make it from the first produced I believe. Those have some design differences that someone with more knowledge than I can help you with.
The ones I have held have a wooden hand guard or heat shield. Does yours?
I noted that those have a different bolt lock assemble cover.
I have never disassembled one so that is about all I could help you with.
I almost bought one a few years back but was persuaded not to based on lack of parts.
Ruger might not offer parts any longer for that prefix. Could be wrong on that.
Anyone out there want to offer up some details about changes in later prefix models.
Bill