Cobra Parts

Interested to hear if anyone has experience with replacing axle parts on a
Cobra Trailer.
Particularly the brake drum (its an 88 model) and wheel bearings.
Question, are these parts which can be interchanged from generic axles or
bought off the shelf in the US? The whole of Germany seems to be on annual
holidays (half their luck!), so waiting around till mid september for them
to come back seems somewhat stupid.

Any half sensible ideas welcomed. :-)
Chris