Wow, thanks for the info everybody! I think I'm gonna pass on the barrel though. First off, my frame is stainless and I was going out on a limb looking at an old blued barrel. I like good shooting guns but sometimes aesthetics wins out too. I'll probably just wait until I find a stainless barrel rather than getting a blued one and having to modify things etc.
If any of you are interested, the barrel I was looking at is a 45 Colt barrel, blued and octagonal. Seller says it's in very good "like new" condition. I'm not sure if I can say where the barrel is advertised though.....not sure if it's against the rules here.
For now however, I suppose I'll keep searching for a stainless 45 Colt barrel, preferably a 10, 12, or 14 inch with sights and without the 410 option.
Thanks again everyone.
If anyone knows if it's OK to post the link of the sale of the barrel, let me know and I'll post it. (sorry for holding back but I don't want to break any rules here.)