Started making a list I found some pages

http://www.pocketmagic.net/tag/sensitive-geiger-tube/

• Detailed info on lots of tubes
• GM: http://www.pocketmagic.net/tag/geiger-muller/
• Sensitive GM: http://www.pocketmagic.net/tag/sensitive-geiger-tube/
• Neutron tag?

http://pico.dreamhosters.com/YG/GeigerCounterEnthusiasts-4/41846.html

• SNM tube summary

For now just detailed on mcmaster tubes:

: small neutron tube

An eBay seller indicates these may have been made by “VNIIRT / Soviet Institute for Scientific Radiation Technology Research”