I understand.
One of the issues I have seen with adding leather to wood is the great unknown of the tanning process used for the leather.
Left on a stock long enough the leather reacts with the wood finish and can suck the oil out of the stock or worse yet, it can severly discolor the wood.
Not good for an original wood stock and again, something that will seriously devalue the worth of the rifle should the OP ever decide to sell it.
It is indeed more expensive to buy a shooting stock but this can save hundreds of dollars if the rifle is ever sold.
If the rifle is ever sold, the shooting stock can be included in the deal as an enticement and when dealing with older original firearms, enticements such as these often add more value to the sale than the retail cost of the purchase.