I did a google search for "reporting marks" "carstens packing" and turned up a page in the February 1919 ORER.
Carstens showed a series 101-108 (5 cars) as refrigerator cars with an internal length of 34'. There were no other dimensions mentioned. There is no car listed as 109 (the one in the photo). THAT one sure doesn't look to me like it has an IL of 34'. Assuming a truck wheelbase of 5', I get an external length of 33'. 109 looks to be an orphan.
There were also 4 tank cars: 100 and 104-106