I'd swear that I saw a Sherpa minibus re-chassised onto something LR based once upon a time - if that was a doable conversion then the LDV Convoy isn't that much different and may be an easier proposition than the Transit with most of the same advantages.
I've also seen a Safari adapted 110 with effectively the same body length as a 130 and something like 12 forward facing seats and the same turning circle as a 110, but with a stupid overhang at the rear.
That one was a special purpose "nature spotting" one that operated entirely offroad though.
P.