I haven't seen one either so what you are talking about is probably doable but you'll need to insulate the diverging tracks so that they do not cause a short.
Irv
Peco makes one in C55 that would fit to your code 80 since their C55 is not true C55 but rather like C80 buried deeper in the ties to look like C55.However,you'd have a slight difference in looks and also,as you said,when you add the four motors that go with them,they are somewhat prohibitive indeed.
Three years ago,I fitted a DCO from Kato's Unitrak line on the club's layout to replace a damaged one at a period the club didn't have much cashflow to dispose of.At first,I was sceptical as to its reliability but it's been there since and still is flawless.The fit was a peace of cake and if I remember well,I only had to shim it with a sheet of paper to match the Peco track height.It does have a different look but is no real pain to disguise.They are dirt cheap compared to the other brands (I've seen some offered at $49 on Ebay) and they come fully powered.They are switched with reversal of polarity (2 wires),so I used a MOMENTARY DPDT switch to actuate it.Also,if you use this,be careful that no dirt goes into the coil slots so that they don't get blocked.