While we never say never with the Carbine, a Standard products slide on an Inland would be highly unlikely. Maybe the other way around, but it might have been a field replacement also. The only record of Inland using SP anything, is gas pistons. If everything else is correct, then we would assume the original slide failed and was replaced. Armourers and depot maintenance personell didn't care about markings, they used what they had so this would explain an anomaly like that one.
You're thinking Saginaw? It's a large S on the inside flat, and the only other marks are a small 9 and 5 on the bottom flat. It's the early-style slide, with the straight cam lug, not angled like a type V.
No, Not Saginaw. That would be SG. Both Winchester and Inlands commonly had "heiroglyphs" stamped on the bottom of the slides. An "S" was one of the letters used frequently. That is quite different from an "S" on the inside, which is Standard Products.
I have one with a large sideways S on the indside, Would it be an inland or a standard products . I have a picture of it but I don't know how to post it. I can send it to someone to post it for me.
We were thinking of the Inland PI underlined slides from a previous post, one of which I posted has a large S on the bottom outside. We suspect these to be steel lot-quality control-inspection stamps, and aren't part of the contractor/subcontractor ID markings. Have to not answer so quickly anymore until we are all on the same page about the location of the markings. I figured Inland44 knows the difference, but I recall what happens when you "assume" something. Good catch by jimb.