Vince,
The "Lutz Ferrando" South American one`s are interesting if they are BLACK paint, might be about +$250 more than a normal black paint camera of the same era
Dealer badges attached to the body, don`t really bring up a value, unless there`s paperwork, bills of sale, full history, then so it might make a camera a bit more valuable to a collector, on a whole the normal everyday Dealer tags don`t increase the cameras value
The only DEALER ENGRAVINGS on Leica`s that bring considerable higher prices for sale for collectors are the NL (Leitz Netherlands) from Dutch supplier Odin which were on cameras from about 1935 till about 1952
Pretty much like Canon <EP> these NL engravings were for Import/Export purposes only and are now very rare (LESS THAN 2,000 cameras made total?)
It`s just a small engraving, but I`ve seen clean examples sell for over $800 per camera
I have one myself, (it`s non-operational and needs to be restored) but it`s more than likely going to be traded soon for another 1946 Stepped Rewind "Crossover" Bearing US Army camera
Tom