I'm doing this conversion right now in my Td5.
110 Td5 renovation thread - Defender Source
As easy as the video makes it seem, there are a couple HUGE things that are just sort of skipped over.
A) Is he really anchoring the seats to the aluminum upstand? There is a cross member that runs behind the upstand that the original seats were bolted to. The old 60/40 bencjh bolts through the aluminum to that steel cross member, The new seats are anchored in different locations. If you anchor to the aluminum floor, and not to the frame there is no structural strength, he's put a large square washer there instead., In an accident it would just tear through the aluminum floor.
B) the rear plate they say "Steel anchor plates were fitted under floorpan" Easier said than done. There isn't any room there to mount to the frame (space for the brackets, but no room to bolt them in) Again, he's just mounting the seats to the aluminum floor. Completely un-safe. Not to mention, with the plywood spacer there, the seats are in an almost vertical position, making them extremely uncomfortable. When you see him in the seat, look at how high up he is in comparison to the door.
There are 2 options to properly fit these seats:
1) lift the body to gain access to the frame and cross members, install the correct crossmember to bolt to the frame and seats, bolt the correct brackets for the rear plate mounting. Now the seats are securely mounted to the frame, not the floor.
2) the route I am going, removing and replacing the rear upstand, which gives access to replacing the crossmember and being able to have clearance to bolt the rear mounting plate brackets in. Modify the front of the inner fender well for clearance of the seats.
In the first photo you can see the old style bench seat front mounts. Compare to the front mounting points for Puma seats in photo 2. They don't line up, and there are actually 4 points to mount the seats and this is affixed directly to the frame. The 2 tab crossmember can be replaced with the Puma one once the upstand is removed.
In the second picture, you can see the rear plate mounts are bolted to the frame crossmember. Unless you lift the body, or remove the upstand (as per photo1) you can't get in there to secure the brackets.
Third photo shows just where the mounting plate will bolt through the floor. Without those brackets, you aren't bolted to the frame.
With his method you do have Puma rear seats, but they are unsafe, and would be uncomfortable to sit in.