Tyler T grips adapters are fine , but the price is skyrocketed now.
There is a lot of beautiful wood target stocks on the market, and all square butt models have the same internal dimensions (Google Hogue, Eagle, Badger, Ahrends, Herrett, Nill, Spegel and so on. I don't make mention of Culina, 44magget and Brown, luxury stocks...)
You are looking for skinner grips.....exactly the opposite of my taste. Be aware that Altamont grips (the current Smith's offer) are too thin yet. I don't think you could find thinner panels.