Good question
Flash. I had some stuff on the US in Northern Ireland which came about through looking into the US Rangers who started up there.
In respect of Scotland, it housed a large number of special forces training centres both for specific organisations and for wider service use. Lochailort, Lock Fyne, Loch Linnhe, Loch Lochy, Inverailort, Arisaig, Arran, Achnacarry, Inveraray and others.
Off the top, I can’t think of any US ground personnel bases, but, American units did spend time in Scotland for training purposes both in joint exercises and on special courses. The Rangers for example, went though Basic Commando Training at Achnacarry and various units spent time at Inverary (stone ship HMS Quebec probably) doing amphibious training. I think something like 250’000 troops from a variety of services passed through Inverarary.
Sorry, not much help.
No.9