Is it a GN-1?

[SWISSNIXIE - Jonathan F.]

I bought a unknown nixie tube for a few bucks, and i would like to find out which one it is. I have attached pictures, the tube is about 6cm long, 4cm diameter and has about 25mm digits. The digits look hand made, or like very early machinery. On the is engraved "35H4", engraved by hand.

It looks very similar to the GN-1, but the both versions of the GN-1 i know, have different grids, one version has no grid, and the other has a different aligned grid.

Maybe mine is a different version, or a whole different model?

Any info would be great! :)