In the long run I'd try and respace it to whatever hubs you're going to be using - AIUI the residual stresses in the chain/seatstays and non-parallel dropouts can cause broken axles and other problems if heavily loaded, and for a tandem that goes double. But I may well be being overly paranoid!
It's only ever going to be used for pootling around the lanes for now. I hear what youre saying though. A 140mm hub would keep everything in line, I just haven't got the readies to shell out on such a wheel.
In the long run I'd try and respace it to whatever hubs you're going to be using - AIUI the residual stresses in the chain/seatstays and non-parallel dropouts can cause broken axles and other problems if heavily loaded, and for a tandem that goes double. But I may well be being overly paranoid!