Hi Karl,
Hope you and the Family are well, i have just finished the Capt side J Rail build i have attached some photos below i had to add a metal plate on top of the MDF due the bearings starting to cut a channel and destroy the MDF, with the metal plate made of sheet steel 1.5mm thick this problem went away. I used a very simple locking mechanism using a spring loaded draw bolt and a locating hole drilled through the metal and MDF works a treat.
I added some additional support under the MDF as it was flexing slightly under load from my fat ass. I have attached a video clip of it working, when are you starting your IPECO seat build buddy.
Hi David I did the same things as you here, added strengtheners underneath either side of the J Rail slots and also added 1.6mm Aluminium sheet on the top for the same reason as could see the bearings wearing into the top. I have designed a lever and template guide to set adjustments fwd/bwd for seat adjustment just waiting on the Iveco seat to be released to complete that mechanism. Have some pics in Sim Showcase - My build begins