It is OEM and I haven't put it on yet got it off a salvage tractor I wanted to add another to mine only have one Thanks for your input
When I put four remotes on my tractor I bought the aftermarket valves sections and two end plates, and just assembled it, without worry about torque on the nuts on the ends of the rods that hold the whole assembly together. I just figured, maybe misguided, and I actually never thought about it, that the O rings between the valve sections would do what they are designed to do, and I was home free. This was about 16 years ago, and no problems have appeared yet. I just snugged up everything the way I thought was reasonable.
So I would suggest that you make sure you get the proper O rings to use when you put the new valve section in. And that you get longer threaded rods (not sure the correct term) to hold the valve sections together, after you add the new section.
If all the hardware is compatable, it is really a simple thing to do.