Hi, I have a Kona Cindercone, I think was 17 inch but has had part of the seat tube removed. Not sure why, was like this when I bought it from ebay and didn't realise/know until I got it! There is no signs of seat post being stuck inside the seat tube so maybe it was removed due to damage? I bought a new (longer) seat post for it and used it for commuting until I got another bike sorted.. The chop down isn't exactly neat but doesn't notice with seat clamp fitted and but I had no problems with post slippage (using an anodised post), however I'm not the heaviest chap.. Had no issues removing the BB, threads appear fine. Have attached a couple pics..
I'm based in Menai Bridge, North Wales and don't really want to use my limited supply of boxes packing it so if anyone wants it they're welcome to it, otherwise it'll go to the tip next month when I have a clear out/move around..
If anyone REALLY wants it I will be travelling to Oswestry, Swindon (Wiltshire) and North Devon end of this month - next month when my van is fixed