I came across these plexiglas filter housings I used to make and thought I would show what can be done machining acrylic with a bit of care.
The OD is 2.600" and the internal chambers are about 1.2"; they look bigger viewed through the curved walls. The hole passing right through the top piece in the first picture is 3/32" going through a distance of 1.78" which is about 19 x dia. The outside was polished in the lathe after machining in two steps; wet sanding with wet&dry emery paper followed by Brasso on a linen cloth.
These were done on a small manual lathe using all hand ground HSS tooling with zero top rake. Lubrication and cooling was with a soap solution.
An open mind is a virtue...so long as all the common sense has not leaked out.