Troop 2nd seat question?

I have seen one at work It didnt look all that cheap. The passenger seat had a lever that swung the seat around giving access to the back seat (not easy access for your grandma) besides that it was comfortable

Only the RV Troopies came with the fold down second seats. Earlier ones were 6 seaters and later ones 5 seaters.

Aftermarket fold down seats are readily available from seating shops. I've enquired with Willshires in Adelaide. Your only other consideration is the tilt forward mechanism on the passengers side is different on the factory RVs to allow easier access to the rear seat.

Having had a couple of 75 series troopies the first one an 11 seater and the second a early "RV' 6 seater I'll give you what I know/learnt.
The 6 seater rear seat is a specific seat for that model and the captive nuts/mounts are in the floor for the rear forward facing seat for that model only.
The 3 & 11 seaters don't have the mounting points for the forward facing rear seat.
In the 11 seater I found a seat from a Toyota van was damn near identical in width (it was a snug fit between the sides). I think it was the rearmost seat from a Hiace commuter. I just drilled the floor in the appropriate spots and fitted plates top and bottom to spread the load. Alternatively you could modfiy the feet to use the original side seat mounting points.
The lower seat belt mounts in the troopy for the side belts were used to mount aftermarket inertia reels and the top mounts were made like the aftermarket mobs do. Then I had to get it engineered and recomplianced for the 'decrease' in seating. (cheaper rego than an 11 seater).
Alternatively you could get an aftermarket seat fitted but at a much higher cost. Depends on whether you have the skill and the time or the money ;-))

I had fitted an aftermarket bench seat . Retractable seat belts each side and lap belt in middle(you can attach a child restraint) ( not that i want to go back to those days LOL) . The seat folds in half and rests up against the two front bucket seats giving you almost as much room in the back as a three seater . I think with this setup i should be able to put in a set of rear _Affordable_Storage_Drawers.aspx and with a bed extention i will have about six foot of sleeping or storage room . If i need to carry more than two people than i just move all the crap to the back , fold down the rear bench seat and hey presto seating for five . Cost me about $1050 installed with certificate .