That teak furniture is made from what appears to be well-seasoned timber. The plant where it is produced also does a lot of teak outdoors furniture (as in the sit-on type furniture) for sale in Europe.
The bigest problem for users is that teak is denser than walnut, thus adding a bit of weight to a completed rifle. For target shooting this is not much of a problem.
I understand that the SMLE stock sets were deliberately made to require final hand fitting. For use with standard weight barrels, the channel needs to be packed at the normal bearing points. This was apparently considered an easier option than supplying two patterns of front wood. Note that the last time I saw them, the stock sets came complete with all the metal buts attached, all you need is the removably bits like nosecap, swivel band etc., including the brass butt plate.
I got the impression that the Oz party would have liked to have done them in walnut, but the economics of labour, material sources and shipping killed that idea.
Making the furniture in the correct timber here in Oz is fraught with problems. I found a source of coachwood and a CNC woodwork shop Then the fun started. this is not a boutique biz. The wood guy talks in tons, the CNC bloke talks in multiples of thousands, and that's before finding a source for all the springs, clips, rivets and caps etc that attach to the wooden bits. I haven't given up yet.