As far as the shop goes, we do still see a fair amount of them in both Husky and Jonsered. There's just so many around here. Jonsereds seem to dominate the early twin coil saws where the later single coil saws are more likely to be Huskys as the local market was shifting a bit. Awful lot of 630s were sold around here. Lot of shops don't like to work on the older saws, but we do. And we have a lot of parts for them, including some NLA bits to keep things going. Some shops have younger techs that don't know these saws and they don't have parts, so they turn them down. We know them front to back, have plenty of parts and don't think of them as "old saws".
As you know these 2 series saws have many more variations within the model range as opposed to the 372/2171 chassis that replaced them. There's how many starter pulleys vs just the one on the 3 series as one example. All the different intakes. Even the 162/630/266 "looks the same" intake has 3 variations with different hardware. So, knowledge and experience come in handy for us cause we've been doing them so long it's all in our heads.
Personally I enjoy them as much as the 372 chassis and run them equally. 372 has an anti-vibe advantage. Other than that it's a coin toss for me. But for whatever reason I always seem to grab the twin coil saws over the singles on the 2 series.
For guys with limited experience or resources, 372's are likely a easier direction to go in as far as sourcing parts goes. And there's a lot of extra value here in this thread that you started cause we're sharing info on all the individual parts not just the complete kit/clone deal.
And even within the 2 series it's much easier to source parts for the second generation single coil saws than the early twin coil models, so that needs to be considered. At least for the newer 61/268/272 Huskys. Jonsered specific stuff is getting scarce quick for all of them.
