I've been using a late relative's spare blowtorch that he left at my
house ~20 years ago. It consists of an orange tank with a valve, a
rubber hose maybe 2 m long, and a handle/outlet with a valve, & two
hose clamps. (I don't use it very often.)

When I used it last week, I had occasional problems with it: switching
between "neat blue flame" & "orange flamethrower", occasionally going
out, & leaving some wet-looking stuff on the nozzle. Does this just
mean the tank is almost empty, or is there something wrong with the
handle/nozzle?

Should I replace it with a newer model? Any recommendations for
occasional plumbing jobs?