I know they were sold with the sealed beams to the front and/or rear but I don't think the factory installed the step mirrors with the inner sealed beams pointing in the same direction. The sealed beams were always on the backside of the step mirrors or in the case of 4 sealed beams, there were NO step mirrors. My guess is yours was a field modification by a previous owner as evidenced by the ends of the step mirrors being bent inward to make room for the bulbs whose inside edge would interfere with the inside edge of the mirror. Also, one side mirror isn't bent inward as much as the other side adding to my speculative beliefs.
Depending on which matrix your bar has, you may be able to add two more sealed beams but the bar may not be able to run all 6 strobes. I don't know if Whelen built their internal harnesses that allowed for expansion in the field. You may only be able to run the fronts OR the rears but not both in addition to the 360's. Correct me if I'm wrong but I don't think they made one where you could run all 6...not enough room under the end bases for enough power supplies?
I did get your message and replied. Back in the day, the units I had, had 4 sealed beams and the 2 360's. I could run the front pair of
PAR's OR the rear pair of
PAR's but not both. One power supply, which was under each end strobe, could run 2 heads. One was for the 360's the other was for one pair of
PAR's OR the other. At least in the matrix that the bars I had, were built with. The old Whelen guys can embellish deeper than I can... I do remember one or two bars being able to run all 4 sealed beams at once but then, not the 360's. Old farts???
And, if I remember correctly, that was due to a field modification
I did to allow for a two-color bar for the towing industry here in WI where we have to run 2 colors for different situations. If memory serves, I think I swapped two of the end strobe connectors for two of the
PAR's to make it happen and get all 4 inners to operate together but again, I would then lose the 360's which were a different color, achieving the matrix we needed to meet the color requirements. Cool bars for their day! Hell, I even took some of the cruise light bulbs out, added #1156 bulbs and installed a #537 flasher for an alternating flash in addition to the alternating strobes. We weren't allowed any steady-burning "warning lights" here anyway, might as well put those lights to use!
Then came the Edges... WHOA, what a concept! But what was with the pink and baby blue?
(sorry, didn't mean to hijack your thread)