I built my 4001 just after I graduated high school. I also made some mistakes but my Dad who was a Ham fixed them for me.
I'm amazed that my Heathkits still work, especially considering - like you said - how caps fail over the years. As far as I can tell, my units are still okay, although I'm sure I'll need to recap them eventually.
You could build the "new" kits and keep the already-built units for spares...or sell them and make a pretty penny. Those unassembled kits always sell well on eBay.
I have the digital barometer but I could never get it to read the pressure correctly. I don't know if some parts were bad or I didn't assemble it correctly. I'm thinking of selling it on eBay. It hasn't been plugged in for decades.
I saved a bunch of Heathkit catalogs. I'll have to see if I have one from 1974 that featured that analog thermometer.
I envy you being a meteorologist. I wanted to be one when I started college but couldn't grasp the math. Somehow I ended up in TV and radio.