Ask your government....they're the ones who forbid surplusing US weapons to it's own citizens.
USGI surplus Garands, 1903s, and 03A3s have been sold by the DCM/CMP for decades, and at this moment in time, still are (but the CMP supply is dwindling).
Actual "lend lease" Garands are uncommon. If you ever found an authentic Garand with lend lease markings and traceable history, it would be worth acquiring.
M1C and M1Ds are also fairly rare, especially with the proper M82(?) scope. The GCA reported that the CMP has new in wrap, unissued M1Ds with scopes, and they will be auctioned off. If you can get a copy of the latest GCA journal (I believe it was in the most recent issue), there are photographs of some of the unissued M1Ds the CMP has.
M1 Carbines were sold by the DCM/CMP a long time ago, but not anymore. Considering more M1 Carbines were manufactured than M1 Garands, I'm actually surprised that more aren't available. Maybe someone with more expertise on the history of the M1 Carbine can comment.
M14s are still in use by the modern US military. Even if they do get phased out, they won't be surplused for civilian purchases due to the fact that ATF pretty much goes by the rule, "once a automatic weapon, always an automatic weapon." So even if the US military surpluses M14s to the CMP, they would be considered Class III automatic weapons even if the CMP were to modify them for semi-auto only.
If the US military were to phase out the M14 and surplus the rifles to the CMP, the CMP could theoretically disassemble the USGI M14 rifles and (1) rebuild them using commercially made civilian M14/M1A receivers or (2) sell off the parts except for the receviers. The parts off USGI M14 rifles are valuable alone considering USGI M14 parts are becoming hard to acquire, and it's the non-USGI, aftermarket parts that are out of spec that are causing the problems experienced in the current SA, Inc M1A rifles.