well...the lugs on a lugged frame really do a job, rather than provide ornamentation. It'd really be cheaper to buy an 80ish or 70ish road bike with horizontal drops and lugs in place, rather than try to build one up from a tig-welded dealie. The assembly of an older steel bike is done (usually) with bronze brazing...it is entirely possible to heat the dropouts to the point of melting the brazing and pull 'em out, and replace 'em with whatever, and re-braze 'em. The frame repair guys do that all of the time...

but...they have the jigs and everything to keep the bike in line, instead of crabbing down the road like that skyed 1964 ford f150 fwd that crashed into the side of the mud bog one too many times. Really. you can get a frame for 10-20 bucks that'll do you for a lugged steel fixie.