Hi Graham
I tow a t/a Abbey 620 with my swb 2.5 Pajero and when towing I inflate the rear tyres to 34lb/square inch on the advice from the tyre fitter.
To overcome the problems with the Al Ko stabiliser handle fouling the door mounted spare wheel I undid the star screws on the red handle which I now keep in the car. I raise the two 'forks' of the stabiliser, hitch up and slide the handle over the forks to engage the stabiliser. As soon as I've engaged the stabiliser my o/h returns the red handle to inside the car so that it is not forgotten because a replacement handle is very expensive.
When un hitching disengage the stabiliser (don't forget to return the handle to the car) and bring the twin 'forks' forward gradually as you wind up so that they don't foul the spare tyre.
There's a bit of a 'knack' to this but after a couple of tries you will be ok.