Rushmore Headlamp information needed

Does anyone have experience with or literature regarding Rushmore headlamps? I have two different size Rushmore headlamp sets, one size is nearly 11" OD and the second is nearly 10" OD. Both of these sets have serial numbers stamped into the front of the chimney, just behind the door. Does the "A" or "B", at the start of the serial number, have any significance regarding the lamp. I had thought originally that the "A" or "B" may refer to the size of the lamp. I now think that it has nothing to do with the size, but maybe year of manufacture. Oh yes, both sizes of lamp have 6 exhaust ports down each side of the chimney. Should all Rushmore headlamps have the sectional flat plate lenses? (I think Yes) What would be the proper size burner for these sizes of Rushmore lamps? I would like to learn any additional trivia or information regarding the Rushmore lamps.

Alan

Got any photos?

I pulled out the Rushmore headlamps and took a couple of pictures from which I base my questions, as per above.

1- Front view of both sizes

2- Side view of both sizes

3- "A" serial no. from the smaller lamp

4- "B" serial no. from the larger lamp

The smaller of the two sets is actually big the larger of the sets is HUGE!

If you have any information, please share.

Al