Just a correction of my previous contribution in which I loosely used the term "brazed up"
Hopefully the Spectrum frame was silver-soldered (UK-Speak) this is silver-brazed (USA-Speak), seeing that the tubing used was Columbus S. Columbus really had "a thing" about the necessity of using silver alloys with these tubes rather than the good old workhorse silicon bronze. Or it it silicon brass in the States?
Norris Lockley...Settle UK