Well, my pat answer to that question is that if you have to ask you don't have the skills. But really, only you can answer the question. I don't know why you wouldn't just use glue.
Those English builders used brass most of the time, and so you are probably not going to be able to take the head tube out of the lugs by melting the filler. Or at least it's going to take a big fire and some firebricks and a lot of luck. There used to be a webpage on the Yellow Jersey website about doing a repair like that. Also, you have to check for pins and drill them out if they are there. One way to attempt it is to cut as much out as possible with a hacksaw and files and then grind out the part of the head tube that is in the lugs. I found a sanding drum in a dremel to be very effective
Once you can get a head tube in the lugs, brazing it in is the easy part.