Happijac bed modfication

Hello, RV'ers Currently have a happijac bed system on my 2012 TH looking to remove picnic table setup and install flip-down benches. I found a pair on eBay but they are a new style slotted rails and my current setup is the older system that used Phillips screws no slots on the trolly The spans between rails are the same distance. did some surfing on the internet check Lippert, Happijac unable to find any information? so I was wonder has anyone made a modification? can you buy new trolleys and be changed to the newer slotted rails or do I have to buy a new rail system big $$$, a, has anyone done a modification so it works with the older trolly system.

Thanks in advance