Difference between SLR and SAM line

Excuse my ignorance, but what is the difference between the SLR and SAM line on models that accept double stack mags?

thanks in advance!

SAM: Made in America as double stack guns.
SLR: Imported from Bulgaria as single stack guns then converted in US to double stack.

SAM: Cleaning rod under barrel.
SLR: No cleaning rod.

SAM: Forged and milled fire control components.
SLR: Cast fire control components.

SLR101S:

http://www.gunsnet.net/album/data//500/22287File0049-med.jpg