So I have bulbs that have missing etches that I have images of or memory of what they looked like... Is there anyway to fabricate an etch stamp and "repair" these lamps? What kind of ink did they even use?

The ink consists of silver and copper oxides in an organic binder containing boric acid.  If you have a rubber stamp made up with the desired layout you can stamp this onto the glass, then heat with a blowtorch flame to about 350C.  This causes the metals to be reduced and permanently etched into the surface of the glass.

The ink can be bought from Glassbond in the UK although they don’t seem to list it anywhere.  It is also still made by GE Ivanhoe Road, Signify Poland and Ledvance Schwabmunchen but they may have bigger minimum order quantities.

The ink consists of silver and copper oxides in an organic binder containing boric acid.  If you have a rubber stamp made up with the desired layout you can stamp this onto the glass, then heat with a blowtorch flame to about 350C.  This causes the metals to be reduced and permanently etched into the surface of the glass.

The ink can be bought from Glassbond in the UK although they don’t seem to list it anywhere.  It is also still made by GE Ivanhoe Road, Signify Poland and Ledvance Schwabmunchen but they may have bigger minimum order quantities.

Not something for the faint hearted to try... 

Not something for the faint hearted to try...  

Not with a rare and irreplaceable lamp, anyway. I'm certainly not putting my one and only MA/V lamp that took me years to find within half a mile of a blowtorch..!
I did fix the loose cap with Gorilla glue, though. Thanks to Andy (Photonicinduction) for that tip  

There are some inbetween solutions, like the computer printed Orange translucent dot matrix (later GE Hungary and Philips style), and the Gold color etches common on Chinese lamps. None of them are really etched into the glass

When I do this I will practice on some cheap sunbeam lamps first or some cheap equivalent. Could I heat the lamp inside a conventional cooking oven?