Before I tear apart my only working bike to find that I have purchased the incorrect BB, is there a simple way to identify the thread type on a bottom bracket? I have a Puch Pathfinder frame, no idea on the age whatsoever, but it is built for 27" wheels. I want to order some new parts, but I don't know how to visually determine the thread type. Thanks for any help.

You can use a thread pitch guage. Little tool, sold at hardware stores. I believe Puch is Austrian, which likely means English threading. You can also try to put a cup of known threading into the shell, but do not not not force it. Another way is to put a cup of known threading next to your cup and see if the threads match, if they do, you will be able to press them together and the threads will insert perfectly into one another. Hold up to light to make sure they are fitting together.

Tried just pulling the cranks and looking for the which is often on the fixed cup? If it's got a 'made i Japan' sticker on it it is english thread.

I'll also remember that Puch have normal English threading.
Take your parts to your local bicycle store and match the threads.

/Martin Olsson