Model 74 Serial# 27986 Recovery|Winchester .22 Rim Fire|Forum|Winchester Collector

Just documenting the recovery of the early Model 74 owned by my Father-In-Law who passed away.  My wife said save it and I said Aye!  So far, didn’t have to breakdown the bolt, but everything else was full of grit and something like mud.  Firing pin looks ok and everything on bolt sides very nicely.  I’ll post a few before photos to start.  These pictures were after I soaked the action in PB Blaster to loosen things so I could get it apart.  Does anyone know what the mud looking stuff is?  It was really thick. It was in an old case under her dad’s bed.  Is this just years of dust mixed with the oil?  I had to scrape it out, brake cleaner wasn’t touching it!