The point of this post, however, is to show the sort of 'modification' that an uninformed person may carry out, and which could result in serious injury.
It appears the bike hasn't had a great deal of use, and that is possibly fortunate - If you look at the attached photos they show the previous owner drilled and tapped the seatpost (presumably so his desired saddle height was easily reproduced). Not only did it cause a huge stress-raiser, but it was also in the worst possible place for the stresses involved, what with being in the front of the seatpin, and (inevitably) at the exact height it emerges from the seat tube. Ironically the previous owner has always been a very nervous and safety-conscious individual (sometimes to the point of being irrational)
I'd advise anyone wishing to frequently remove their seatpin, but return it to correct height to either mark it with paint, put tape around it, or (as long as they don't damage the surface) use another seat clamp or jubilee clip as an indicator/stop. I've bought a new seatpin, and put the old one in the scrap - I may even saw it in half just to prevent someone somehow retrieving it and 'recycling' it.
