(I later received a comment from one of the founders of Specialized, Bryant Bainbridge, part of that is posted below*. He straitened out the facts, including, The notion that Specialized didn't design anything is pure crap!)
Also posted is another suspected 3Rensho frame.
The only info I have to add to the previous thread is from one of my mechanics. He says that the 3Rensho-built bikes have a slight slope to the fork crown (mine does) while the rest of the Allez line has a flat fork crown.
*portion of comment by Bryant Bainbridge
The very first Allez's indeed came from Yoshi Kono and can be identified by the offset fork crown and long, super thin point lugs. Yoshi made these bikes for just a short period which I think ended in 1983. He made road, track and just a very small handful of funny bikes (less than 10).
The notion that Specialized didn't design anything is pure crap. From the beginning some very fine framebuilders were employed to design bikes. Tim Neenan was first (Lighthouse frames), Jim Merz second and later Mark Dinucci joined our team. Mark is the man behind the thousands of frames made under the Strawberry label in the Pacific Northwest and later under his own brand. Among framebuilders his work is highly respected and folks like Sacha White at Vanilla speak of him with reverence. The details were sweated and that was what made these frame successful in the early days. At that time there was no middle ground, you either bought custom or settled for marginal fit and geometry.
Based on my bike and other posts, I have identified the following traits that would indicate an Allez was made by 3Rensho. The basics are it came from the factory as a steel lugged frame and fork painted red. There is a slope to the fork crown. The bike has chromed Campy dropouts front and back. The frame is built with a Medalist bottom bracket shell and has no serial number. The only number on the shell is the frame size in centimeters (mine is a 56).
An interesting note on my frame was the bike came with a Suntour front derailleur, a Campy bottom bracket, and a Shimano 600 headset. When I removed the headset I found that the bottom of the head tube had not been faced. There was a bit of brazing material plugging up the head tube, but that did not stop someone from pounding the cup into the head tube anyway. Fortunately it did no harm to the frame and Paul @ Rocklobster Cycles was able mill and face the head tube. Since the frame was set up for JIS, Paul machined the head tube and fork to accept the Campy headset I was going to install.
The main problem with the 3Rensho frame is I have yet to find anyone you will stand up and say this is a confirmed 3Rensho frame and this is what it looks like. I’ll add more to this post as I learn more.
I received a post that this bike was not a 3Rensho because the fork was not offset. I'm not sure how he could tell with the tiny picture I posted, so I posted another showing the fork is obviously offset.