Crosman 600 Vintage Semi-Auto Pistol - seal kit o-ring sizes

I'm excited, I think I got version One which is presumably the rarest. I compared the photo of the end cap (the pistol is being shipped still) to the end caps in this article below, and looks like it has the screw-in piercing type. 




ARTICLE ON THE HISTORY OF THE 600: 

http://www.pistolplace.com/2015/07/14/vintage-air-pistol-review-the-crosman-model-600-and-model-677-plink-o-matic/ 

from the article: ".....There were three main variations in the Model 600 during its production life. Changes were mainly focused on CO2 piercing. On the first models the CO2 piercing pin was incorporated in the end cap, and the CO2 cartridge was inserted with the neck facing outwards (towards the end cap). From around 1964, CO2 piercing was incorporated into the firing valve, and CO2 was inserted with the neck facing inwards (away from the end cap). Up to 1966 the end cap was a plain screw-in type with a hole through which the CO2 cartridge could be seen, but from 1966 – 1970 a button type end cap (similar to the end cap used on the Crosman Mark 1) was used. However, Crosman service stations were instructed to replace earlier CO2 piercing system with the later versions if a Model 600 was returned for repair. So, many early 600s may have been retrofitted with one of the later CO2 piercing systems....."

Thanks ajshoots. Called him last night and a rebuild costs $75 including parts and rebuilt valve. Reasonable. But I want to try doing it first myself for fun...and for a challenge. There are a couple of great DIY guides on the net.