The 529983 was started from an Accurail 5600 series exterior post car. I kept the sides and under frame. The ends are cast resin modifiedfrtm a 5277 end to the smaller size for 529983’s 5029CF size. The roof is an Athearn Genesis PS bowtie roof available from Cannon & Co.
I picked 529983 because it is the only Southern car I have seen with the Evans AirPak logo. There were 25 or so cars from I think the 33000 series sent to Evans to have the AirPak dividers added and the cars upgraded to 100 ton with a truck change as well.
Wherever I found the pic of 529983 I do not remember, might be George Elwood’s site.
The clinic also included the CofG 3500 series boxcars.