Single Point Sight

Looking for detailed info re the Single Point sights mfg in the UK starting in 1968. 50 Single Point sights were purchased from ArmaLite Costa Mesa CA for the Son Tay Raid in 1970. At the time there were two different rifle models, one had a red element for day/dusk and the second had a green element for day/night. Photos of the SF who participated in the raid indicate the domes were round and clear. Some Single Points, mine included, have frosted round domes with green elements that may be tritium powered. What I'm looking for is detailed info on the early Single Points thru 1971 and later if possible, hopefully a MILSURPS member from England knows a lot more than what I'v so far been able to find on the net. There has been a discussion on AR15.com re the Single Points and there is still quite a bit of speculation re the use of tritium. ArmaLite notified customers. both law enforcement and civilian, that the beta powered sights were no longer available for sale late/Dec 1970 and could only be sold to the US military.