Due to the very unfortunate absence of one of the more esteemed members of this list, I feel it my duty to fill in some gaps in the 1 1/8th Top Tube discussion, namely, that tapered top tubes were probably invented to get around the joint issue with old frames.
Selbach's "Improved Taper Tube Frames" used (and I quote):
TOP TUBE ... ... 1 1/8-ins. tapering to 1-in DOWN TUBE ... ... 1 3/8-ins. tapering to 1 1/8-ins SEAT TUBE ... ... 1 3/8-ins. tapering to 1 1/8-ins
Represents the "LAST WORD" in scientific cycle frame construction. Each frame is built throughout with Reynolds' Best Quality Gauge Tubing. Frame whip is eliminated.
For lack of any proper framebuilding experience, I'm guessing that standard lugs could be used on such a frame.
Wish I had one for comparison.