Great news. Armson USA has 2 upgrades available  for these older units. First is relamping .
New tritium.  And they are working on and have available some new color dots.
The fee is fantastic.  $39.95 plus return shipping
The second upgrade is the replacement of the adjusting screws/ turrets
To a more user friendly experience.  $29.95 plus return shipping 
for that service .
New dot color from my understanding is  1 yellow/Green


I'm not affiliated with Armson USA
Just excited to get my long since dead tritium replaced
And have this fantastic aiming device back on line. Night fire without batteries  or night vision is  $$$  friendly.
JP
Side note for a2 retro
These units are 100% correct for an A2 . They were adopted by USMC and used in Panama invasion 1989.OEG was used by the Marines in Panama, Desert Shield, and Desert Storm in particular.

https://images.guru/i/dkLug

thanks

I sent one back to have the tritium, replaced maybe 2 years ago. They did a great job.

Yep. Great people. They take pride in their work.

Got my unit back.
Fast turn around.  Clear as a bell.
New Tritium.
I'm loving it.
JP