How common, or rare, are the early italian engines?

[Paul Hail]

Somewhat connected to my previous post, how common or rare are the earliest italian engines?  It seems like K88's are fairly common, and you occasionally see Parilla SS20's, but I don't ever recall seeing the 60's vintage Komets and Parillas on ebay.  I don't check ebay every week, but have searched used kart engines now and again over the years.  

If they are as rare as hens teeth, I have a better appreciation of the VKA's stance of not allowing them in classes that they would both dominate, and that only a few folks would be able to run the engines in.

[David Luciani]

not super rare but they are hard to come by. 
i know a few people with big stashes.
i have a couple but don't really look for them much.
d