I would convert it if you have the time and the space. The best thing to do is to cut out the right hand side of the bulkhead out of the old van, and weld it over the existing bulkhead of the new van. That will give you all the mouldings/holes etc that you require to adapt the steering, and foot pedals etc. The best way to do this is to cut the section out by grinder, take off the existing spot-welded flange by drilling out the spot-welds. Then weld it through the drilled holes, plus drill and weld any more you feel are needed. This will replicate the spot-weld effect on your bulkhead. You will need to take the wings and inner wings off both vehicles to get the full panel, and make it more like a RHD bulkhead.
Is your hand brake floor mounted or beside the steering column? Easier to stick to the floor mounted as you will require a shaped piece of steel welded to the right hand front chassis member, a mirror image of what may be present on your LHD chassis, to take the bowden part of the brake cable.
It will be a lot of work, but worth it as I do have visibility issues at times driving my LHD F4, and given the opportunity, I would convert.