Can anyone ID this antique painted glass lamp?

Please excuse the stuff in the background, but does anyone have any ideas on who may have manufactured this antique lamp? It's my Dad's and he sent me this pictures. His eyesight is pretty poor, but he said the markings look like an L and J maybe? I haven't seen it in person yet to confirm. Any help is appreciated... thanks!

 

Bottom of lamp base.

 

This is it flipped. I see a I. L am

 

That's very pretty.
The glass may have been made by one company and the base by a metal foundry.

1920s.
Could be French or Czech.

@Brazos
Can't think of the other lamp person.

@verybrad

 

Not a lot of information out there on lamps like this. Best known company that did them was Pairpoint but think it should be marked as such. The base mark shown does not mean anything to me. It could be just a foundry mark.

I actually have a pretty similar shade that is also unmarked. I purchased it along with a well marked Pairpoint puffy shade. They came in to the local thrift as NOS from a long time lighting company here. As much as I would like to attribute it to Pairpoint as well, I am hesitant to do so.

 

Just an inverted take on it!!

 

I got a chance to look at it in person and can't find markings on the shade or the cast. I think foundry marks was the correct answer to what my Dad thought was letters. Thank you all for your help!

 

Assuming it has it's original socket, you can determine a lot about the age, country of origin. A photo of the socket could assist us.