My tow vehicle (Subaru Forester) is wired for towing. It's fed through a 3 to 2 converter box from the separate tail/brake/turn lamps to standard flat four connector. Works just fine for a trailer that's set up with the combined tail/brake/turn lamps.
I have an old British car I'm going to flat tow. It's set up is a combined brake/tail light. (dual filiment bulbs red lens) and separate turn signal lamps (single filiment bulbs amber lens)
What I'm wondering is, can I take the signals from the flat four connector and run 'em through a 2 to 3 converter box separating the signals for me?

I'm trying to make the whole thing plug 'n play for towing either a standard trailer or my British car.