I have wondered about the importance of construction material for organ
pipes.  Back in the 1940's they made clarinets out of metal (instead
of grenadilla wood) and most musicians considered them junk.

However, I once saw a repair technician punch holes in a garden hose,
put a clarinet mouthpiece on one end and a funnel on the other and
made an absolutely beautiful clarinet tone (I was a clarinet major
in college).  Of course the notes were out of tune, due to inaccurate
placement and size of the tone holes, but the tone was excellent.

Perhaps this could apply to organ pipe material also.  I have wondered
about constructing pipes from PVC tubing.

Dick Day