Newdog..............I don't post here much but I've been into this hobby for 10 years. There is a lot to learn with Garands and while there are plenty of books on the subject, trying to determine what a particular gun is worth is determined by how rare it is.
Problem is that most of the guns have no written history to follow. Other than the serial number, which will tell you when it was made, however where it went and where it was used is mostly pure speculation.
The CMPhas established some grades (primarily Correct Grade or collector grade) which were sold when they became available. Almost all of them were produced by SA or HRA during the production run from 1952-1956. These can be documented with CMP paperwork however where they went and how they were used is mostly speculation, but most were returned from The Greek govenment.
Sorry...............I got side tracked
Most of us have been "restoring" our CMP garands. We get a mostly correct Service Grade and replace incorrect parts with the correct era parts and hope that now the gun is worth more money........ but that is not always the case.(at least not now) If you hold onto the gun for say, another 5 years, when CMP runs out of them, then the value may go up.
Your SA with the 47 barrel could have been part of the Post War (WWII) rebuild program (1946-1948 i believe) but it's difficult to tell if the stock has since been replaced (which usually had Arsenal cartouches showing the rebuild location). If it can't be proved it is just another Garand.
Your CMP special.......It's too earily to tell if they will increase in value. My guess is "NOT"....Reason? Collectors are into "Original Production"....
I hope I didn't bore you too deathI just "scratched the surface" but this is a fun hobby............