Hi Rob, Bought one in the early 80's as a Model S.I. and it worked great for 20 years until the battery would no longer hold a charge and I still have it. I remember how well it worked for those repairs without needing to get out the extension cord. Just ordered one off Ebay. Stay safe. 73 WJ3U
Long ago (late '80s) I bought a similar cordless soldering iron from Radio Shack. I had to replace battery (late '90s) and opened case to discover it was made by Wahl, Inc. just down the road from me (Rockford, IL) in Sterling, IL. Still there today. Good stuff. Still have it today (Chamberlain, SD). I think ISO-TIP was a TM of Wahl for a while, but ICBW.
I didn't know Iso-tip was still around, good to see they are. I had one many years ago in the shop I used to work in, it was orange color back then. Every once in a great while battery operated soldering would be beneficial. I have used butane models of soldering irons in the past, but they were not that great.