Did a strip down & taken a look at all the parts. Pretty much all age appropriate XT - headset, rear hub, crankset, rear mech & front brake. BB not playing at the mo & haven't got a 40mm spanner yet to remove headset & check bearings - my first 1 1/4"! Suntour front mech jars a little so will likely change that. Rear brake is DX but looks pretty much the same as the XT so will probably stay.
Think I've got the mismatched wheels & hubs sorted. Got a nice set of 231's on Hope Ti hubs from 2manyoranges which I was going to put on another build but think they will go on this instead.