Welcome to the forum! A Winchester would be GI. Inland, Standard Products, Saginaw, Rock-Ola, National Postal Meter, Quality Hardware, Underwood, IBM, irwin-Pederson.
Some common commercial copies are: Auto Ordnance/Kahr, Iver Johnson, Plainfield, Alpine, Universal, and Erma. Iver Johnson, Plainfield, Alpine and a couple others parts are interchangeable with USGI and use some surplus parts. Universal and Auto Ordnance are not interchangeable with USGI parts.
GI carbines will hold or continue to appreciate in value, besides being a part of history. Commercial loose value. GI carbines have forged receivers, and are stronger. The commercial ones have cast receivers.