Are your Cometes in good shape? I bought a Comete frame from the bay last year and when it came it had cracks in the lugs at the top and bottom of both the seat stays. I sent it back as I had visions of myself skewering my behind on a broken seat stay.
If it was the one I'm thinking off in Surrey (£250), then it did look a bit rough in the photos!
Mine has a 12mm hairline crack in the left stay top lug that has been there for over 20 years - I garaged it for 10 years because of it!
In the summer, I decided to 'man up' and put it back on the road and have since covered over 1000 miles commuting on it. During that time I have kept a close eye on the lugs.
Just before Christmas, the bike was T-boned by a car at around 20mph, knocking me off sideways and damaging both wheels with the frame taking the brunt of the impact. However, I have got it back on the road and after very close examination, to my amazement, can see no further cracking anywhere and the existing crack is no bigger.