Nostalgia & History > Builder info for 1960s 30K gallon ethylene tank cars

Long time reader, first time poster. I'm looking for builder information for tank cars from the mid-1960s with AAR code T678 that carried ethylene refrigerated liquid and a capacity 30,000 gallons. Have not been able to find anything from existing photos, STB recordations, UMLER, etc. Based on large format photos, I did find build dates from May to June of 1966 for NPCX cars that seem to be the original reporting marks. They seem related to the UTLX liquid oxygen cars also built in the mid 1960s but have different tank saddles and other details.

If anyone has any information as to the builder I'd be much obliged. 

Matt

Are you aware of the Modern Freight Car List? Lots of knowledgeable ppl there.
https://groups.io/g/MFCL/topics

CPR_4000 Wrote:
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> Are you aware of the Modern Freight Car List? Lots
> of knowledgeable ppl there.
> https://groups.io/g/MFCL/topics

Many thanks CPR_4000 for the reminder about the MFCL group. Have visited there a long time ago and will ask them.