1) acrylic 2) anyone familiar with machining saxophone MP bores?

Not much help, but I know acrylic doesn't like ammonia either...and I'm sure
that's not your problem.

Someone mentioned cast acrylic...is there a way to find out if your acrylic
rod was cast or extruded?

The sheet forms of acrylic can be fairly quickly identified as to cast or
extruded (CP = continuous processed).

I'm not familiar with their behavior regarding machining, although I do
recall instructions regarding machining.

Not knowing what brand you obtained (you reduced your description to generic
by mixing brand names; Lucite, Perspex), it may or may not be helpful to
check the various web sites or search engines....Ato-Haas and Cyro both have
technical bulletins (I think I actually got mine by mail) discussing their
sheet acrylic.

While on the topic of machining musical instrument mouthpieces, anyone know
anything about characteristics of the bore on saxophone mouthpieces?

Thanks

Murray