The PSC leaf springs are their p/n 357. Photo follows...
Good eye! They're Intermountain wheelsets. I have Gargraves/Ross track throughout. Their rail cross section I've found to be compatible with the I/M scale wheels...sometimes. I found scale wheels work best on a tail car since there is minimal axial load to the car in use. Ergo, they track very well through turnouts, crossings, etc. And, of course, they look nicer with the smaller flanges.
As for the couplers.... Well, the ol' lobster claws go with my territory. If I hit the lottery Powerball someday...and bathe in the Fountain of Youth for several years to gain another, say, 15 years of life and dexterity...I may convert my fleet of eleventy-seventy cars/locos to Kadees. I do think, however, I'll dispense with the 'thumbtacks' on the 'beese, at least.
BTW, the couplers are Weaver diecast, body (center sill) mounted to pivot about 9/16" beyond the truck pivot point. A couple of L-bent music wires keep them spring-centered.
Actually, the photos in my first response, above, are of the second Ambroid/QC ATSF caboose kit I built. Here's both for comparison...
The 1309 prototype I found in a photo from Stephen Priest's Santa Fe Waycars book. It reflects a simple modification to combat aging applied to some cars of this series; a steel strap mounted along the middle and bottom of each side. For my simulation it was four strips of styrene with punched rivet detail...a tad oversize, I'll admit, but good enough.
The other construction detail I provided on car 1309 was battery power (Evan Designs) for the LED markers (Tomar). I had attached a center rail pickup roller on one truck of car 1089, but have not been happy with the drag it adds to that car's rolling quality. After the success of using battery power on a B&O 'boose build (Also Ambroid/QC kit) I used the same technique on car 1309.
To gain access for maintenance, removable roofs on these cars was NOT an option for me. It unnecessarily complicates the build and post-finishing access due to the ladders, grabs, etc. that connect to body and roof. Instead, I made one whole car side removable. It's held in place with 6-7 1/8" dia. super magnets (neodymium). The following photo is somewhat self-explanatory...
The magnets are in the body side supports. They align with the clipped heads of small flathead nails CA'd to the inside of the car side. You can see the slight counterbore in the side supports to accommodate the nail heads. The battery holder (2032 batt) is above the truck, the click-on/click-off push button to its left. The push button is part of the Evans Design package and has an extension glued to the button to reach below the car floor. You can see the black button extension just to the left of the floor cross-beam, to the right of the triple valve. The button, believe it or not, is easily reached with my finger without removing the car from the track!
Oh, yes, Mark... One other comment re the wheels on car 1089: they're from an old Athearn die cast metal truck kit. Before using the Intermountain wheels, I tried the older (1950's-60's?) Athearn wheels, since their flanges were deeper than the NMRA scale standard of today, but shallower than typical tinplate. They work as well as the I/M's on Ross/Gargraves, of course!
But, after putting this response together and looking at the photos again....those coupler thumbtacks have got to go! And I may re-mount them to reduce their extension beyond the end sill. Talk about distractions!