I've got three PPI Art Series amps and two spacers, and I'd like to
connect them all together so they look like one long amp.  The spacers
fit nicely between the amps, but I can't figure out how to attach them
in place.  I thought they might use the screws that hold the endplates
onto the amps, but once the spacers are in place, those screws aren't
accessible.

I know I'm talking about ten-year old parts here, but does anyone
remember how they worked?

Thanks,
Scott Gardner