The company was started by 2 German immigrants, Penzel and Mueller, in the early 1890's in Long Island City NY. They offered a variety of clarinets and flutes, as well as some saxes and brass which I suspect were made by someone else and stencilled with the PM logo. If someone can shed more light, please do! The company operated through the late 1950's (as best I can determine), before ceasing production.
Their clarinets (especially the Artist, Studio Recording, and Super Brilliante models) were top of the line horns, easily comparable to anything coming out of Europe during the period. Woody Herman played an Artist model, in fact. The tone was more 'American' than 'French' in concept - think Conn rather than Buffet - great for Jazz as well as concert music, freeblowing, more direct than sweet. Intonation is very good on most of the horns I've tried, and the keywork is comfortable unless you have very small hands: there's a bit of a spread, which is welcome for us large fingered folk!
A customer in Texas was kind enough to forward a model/price list from their 1955 catalog:
Super Brilliante $340
Artist, new model $265
Bel Canto $185
American Professional $165
Standard Model $129.50
The only one I've worked on that I don't see here is the 'Studio Recording' model, which was a pro horn that came with 3 barrels. Perhaps it had been discontinued by 1955? Anyway, I hope this is enough to get you to keep an eye out for one of the better PM's in good playing condition. Regardless of the style you play, I believe you'd enjoy it.