HMV Barn Project

[ppppenguin]

In addition to Jeffreys post I'd say 90% of pre PCB radio and TV's used tag strips in construction. I always snip out the offending components first then either use a solder sucker or desoldering braid to remove excess solder and then unravel the residual wire.
This can even be done with care on B9A or B7G valve sockets. It's always much better to feed the new component into the tags and do the mechanical joint rather than just relying on solder or splicing into existing components leads, that is untidy and leads to dry joints in my view.

Trevor has much more repair experience than me and I fully respect this. (I design electronic stuff for a living, I'm OK at repairs but not a pro) Having said all this I've found out the hard way that B9A etc valveholder contacts can be quite fragile and sometimes prefer not to stress them by unwinding a component lead. A splice to an existing component lead may not look so nice but it's possible to make a decent mechanical joint before soldering. Another alternative is to cut the old component lead close to the tag and wrap the new lead around the tag once. Again not so elegant as Trevor's best practice but normally perfectly OK.

If you're not experienced in dealing with replacing components a bit of practice on a scrap set will pay dividends. You will learn when things will break, how to get decent soldered joints etc.