As best I can figure, Malm's is *not* just rebottled Meguiar's stuff. The Malm's Chemical Company has been in business for quite a while. Can I *prove* it's not Meguair's? No, but I don't think anybody can prove that it *is* either
I used a *LOT* of their polish and wax in the '80s, bought it by the gallon. Got my first Cyclo through them too.
The wax is pretty good, and no staining on rubber/plastic trim. Good beading when used on a properly prepped surface. Very user-friendly by hand and machine, pretty much foolproof. Dunno about durability because I was applying it all the time back then. I can't think of any real criticisms of the product...it's simply a good liquid carnauba, no more and no less. I bet that people here would be surprised at how decent it is....label it "exotic expert-detailer super-stuff" and maybe it'd seem more impressive

How different is it from Meg's #26 (liquid)? I dunno..how different are two yellow liquid carnauba waxes gonna be? Maybe a side-by-side would prove something :nixweiss
Their polish is a good medium-strength abrasive with no filling that I could discern. But it's a bit hard to buff off the residue, the product shows its age that way as a lot of abrasives from the late '70s/early '80s were like that. Cleans up with water and seems low in solvents. Might not give a truly perfect ready-to-wax finish on some soft paints, but IMO it'll only be noticeable on dark colors. I can't think of any directly comparable Meguiar's polish (the Malm's is much better by hand than #83 IMO). Maybe it's like 3M FI-II, if anybody still remembers that one.
Their #10 glaze is a very mild polish with some wax/fillers. It was a nice addition to the above polish back when it came out ('80s) but these days I bet most people would be happier with VM (milder than the #10) or some other "modern" product like that; I reach for 1Z's WaxPolishSoft for instance. Meguiar's equivalent would be #9 or #82, but the #10 isn't all *that* similar to them IMO.
I dunno if there's any really compelling reason to buy some Malm's instead of some other brand's stuff, but it's not like you'd go wrong with it either. Bearing in mind that we're only talking about three products (two polishes and one wax), if you can't get something looking good with Malm's then you're either looking at a *major*-correction type of detail or you need to refine your technique. I think I'd recommend Malm's before I'd recommend Griot's line of Machine Polishes and their BOS wax, but that's the comparison that comes most readily to mind.