How did this go in the end?
I bought all 3 and then looked long and hard at that rear one. More than once. I did notice (at the scrapyard) that access was a whole lot better with the inlet manifold off.
Anyway - I bottled it and talked the local drive-in autocentre in to fitting them for me.... They quoted 1 hours labour but took 2 hours and we settled on 1 1/2 hours. Money well spent - what a b!tch of a job and I would have had a horrible day if I had tackled that on the drive with axle stands.