the lgu / lgv's are 2 different rifles from that perspective, if memory serves me right (not a sure thing these days....) the lgv has a sort of rocker plate that sits on 2 springs that is part of the stock while certainly for my lgu varmint it looks to be that the mechanism slides on the stock, however I am sure one of the many experts that we have on here will be able to put it more succinctly than my noob ramblings.....
I had a brief chat with Armex as I did want to get a synthetic stock for my lgv and they said they didn't supply them (the stocks) but you could get a century with a synthetic stock and swap them over if desired.....