Steve, Beautiful pics. I'm just guessing, but these look more like SW-9s to me or maybe TR-6. They appear identical to me of what SP was using in the L.A.-San Berdoo area to service ex-PE trackage in the 60s and early 70s. The stack, bell, number board and horn placement are identical, except of course, they were orange, silver and black. I seem to recall the SW-1200 being nearly identical to the overly ubiquitous SW-1500. When I remember them they had 4600 numbers, and again I'm guessing that as the really old switchers were retired, these got the lower number slots that were held by the oldies. I used to have special instructions that gave me better answers. I'm assuming that this yard is now utilized by Carrizo Gorge Railway or San Diego Northern now.