Boys will be boys.
It's certainly doable but the end result is nothing short of ugly.
CAR-15 Enfield stock adaptors are available from a couple of places that I know of. They are expensive, $200-$250 depending on who you get it from. These are the butt stock adaptors only. You'd have to supply the fore end and the AR butt stock at additional cost. Total it all up and it could run you $350-$400 plus shipping and you would end up with something like this.
The guy that built this also did a 45 ACP conversion on it at the same time. He makes and sells the AR stock adaptor but the website says he is out of stock.
http://www.specialinterestarms.com/index.php?page=enfield_accessories
The other site that sells them is Survival Arms in Australia. They go for $250.00
http://www.survivalarms.com.au/comp...859/option,com_virtuemart/Itemid,29/vmcchk,1/
You can get an ATI polymer stock set for about $80.00. You can save the Monte Carlo butt stock in case the AR stock loses its appeal.