John,
The RPO 53 was not a San Juan RPO, but used on the Chili Line trains and other shorts.
What the Friends have is the 54 and 65 Long RPO that were rebuilt in 1936 and 1937 for the "modernized" San Juan and Shavano train sets.
But that's all they have from that equipment.
The D&S Stands a better chance of recreating a San Juan. They only thing they are lacking is a proper Baggage car. That will be a trick as the only remaining San Juan / Shavano Baggage car is the 168 on the ground in Golden. It's prtty rough and belongs to another group
Kevin Cook