I wouldn't spend loads getting a favourite standard production frame repaired. It's cheaper just to look for another identical frame/bike and swap parts over. I don't ride super-rare or custom-built frames though, and almost all were bought used so don't have the sentimental value of something you may have had from new many years ago.
If one of mine suffers damage or corrosion, I'll either relegate it to hack use (say if a frame tube gets dented and looks unsightly but is still safe to ride) or if unsafe I'll scrap it after salvaging anything fit for further use like forks, headset, BB unit - then replace like-for-like secondhand.
The Triggers Broom question is one every old vehicle or bike owner may have to wrestle with. If you replace a major part, is it still the same vehicle? For me it depends on what else is still original, apart from the frame/chassis. if the mechanicals are a mish-mash of replacements on an original frame/chassis then you change that as well, all you've got is a bitsa. It might ride/drive perfectly ok but there's no direct historic connection back to when it left the factory.
It comes down to how much ownership enjoyment derives from the history of the thing, and how much derives from the way it handles and feels to use. If mostly the latter, then a replacement clone is just as good. If history matters most then you need to salvage as much originality as you can.