Welcome to the Forum.
"I contacted S&W and asked for any info on recalls etc. and they told me that they don't keep records on the s/n that fr back."
I don't know who you talked to, but the factory historian, Roy Jinks, has records that go back into the 1800s.
I've never heard of a recall on the M13. There were recalls on the L frame .357s and on some of the M624 .44 Specials.
Also, do a search on this forum for "model 13". You'll be reading for quite a while.
"It is a Model 13-2, with a 4" bull barrel, plain non-adjustable sights, an an "unshrouded" ejector rod. A friend of mine told me it was known as the "FBI model", because that was what their agents were issued back in the 1970s or 1980s, before they went to semi-automatics."
The FBI once issued 3" round butt M13s, not the 4" square butt versions.