[VAC] Curtain rail aluminum extrusion source?

[John Leggett <pklhead2@xxxxxxxxx>]

I'm looking for a cost-effective source for the lower
aluminum curtain tracks (or reasonable facsimile) as
used on the 2001 Airstreams.  I need lengths 50", 42"
& 26".  Measures about 5/8" wide with 1/4" groove for
a "T"-shaped button to run in.

Local RV supply/dealers tell me the aluminum is
stocked in 10' or 12' lengths and as a result must be
shipped by truck at a cost 3 times the value of the
material.  ($60 bucks to ship a $15 part).  UPS limits
at 8' length.  And nobody wants to cut a piece to meet
UPS limits.

Any sources or ideas?

Thanks,
John Leggett
1968 Safari
San Francisco area