.
A proper stock is sometimes available on E-Bay but there might be some shipping problems if it is in the USA. You also need the proper nose cap, middle band, and rear sling leather tab and buckle. This will probably take a bit of time to find.
It might pay to put a "Want to Buy" post in the Equipment Exchange, send an Inquiry to Elwood Epps, and attend a lot of Gun Shows. You just might get lucky.
There was a large production in 1918, and there were close to 15,000 of these Carbines made in that year.