No I don't, This setup doesn't look like any dual fuel system I am familiar with.
Most of the info I found was using a carburetor to run both fuels. I didn't see anything about how to do that with fuel injection. It does occur to me that it may not be dual fuel but instead just propane injection like they do on diesels. Otherwise I don't see a great way to turn off the injectors to switch fuels.
I believe that adding lpg to diesel engines is done to increase power (rather like NOx in a petrol engine) rather than replace the main fuel. It was pioneered in Australia to give their "Road Trains" a bit more "umph" for climbing gradients and overtaking timid tourists in the "outback".but instead just propane injection like they do on diesels.
The Cherokee 4.0 that I had was a 1997 converted to dual fuel in 1999, it had a small "black box" installed that shut off the injectors when temperature was reached for the lpg to take over.
The system that we can see in the OP's pictures seems to be missing the computer control system together with the combined lpg level indicator, usually 4 green led's going out as the level dropped, and switch to turn the lpg system on/off.
It would be interesting to know where the red wire from the solenoid terminates.
Sounds like it could be as easy as running the LPG through the injectors and using a fuel shut off solenoid on the fuel line before the fuel rail with a fuel pump kill switch so the pump doesn't run. If one paid attention, that could likely be a manual set up.