My info agrees with Bill's.
That Continental 75 was not the more common C-75-12 of today, that can have starter and gen. mounted. It was an A-75 which is little more then an A-65 that is turned faster... without provision for electrics. That would be most similar to the C-75-8. It is worth noting that the Type Data sheet for the LCA does not list the "C" series engines but I think there is a Continental memo somewhere that equates the "A" & "C" ... maybe someone can add that.
Continental was not yet making any "C" engines, only "A". As I understand it Continental, at that time, was reluctant to make the modifications Culver requested for mounting electric accessories. "Air Cooled Motors" (aka - Franklin) on the other hand offered electrics.
The LFA was the 'special' and was probably a product of the Culver dealer's sales pressure. Radios and night flying lights were still rare in this size airplane. Some radios were very heavy... making a well equiped LFA effectivly a single place airplane.
The electrical alternative for the LCA owner was a wind driven generator (2 are listed in the TC). I have not seen an installation but know that at least one location used was the RH leading edge in the sheetmetal just outboard of the wheel well. The same location as the landing light in the LH wing.
With WW-II looming on the horizon and the name "CADET" clearly a hope of military trainer contracts, radios and electric systems would be essential. When the PQ-8 program began and radio control was being installed they saw that a generator failure would result in the loss of an airplane. Franklin was willing to modify the 90hp for dual generators and the military designation for that engine was YO-200-1 (ie: AC4-199 w/2 gens.). It is interesting that Culver also made a plate between the oil pan and the carb that tapped engine vacuum as a back-up to the engine driven vacuum pump (which failure would also cost an airplane).