Bob,
The seats were standard Heywood-Wakefield recliners and were common as dirt on the streamlined cars. Replicating them should be no problem.
But as the stream of thought goes on, why do it? The San Juan cars lost a lot of class (and capacity) when those seats were installed. Why change them back to that ugly half-old/half-new decor? Just rebuild the vestibules and if you really think that reclining seats are necessary on a day-trip, get them from a from of transportation that is also 8' feet in width... like Greyhound.
Rick