I had to look through the archives for William's original post about his Vanderbilt tender.??
A couple of years ago I bought a partially built Bowser (Redlands) NYC K11 kit that came with a partially assembled Vanderbilt tender with what I believe are Athearn Buckeye trucks.
What follows is supposition on my part.? Corrections most appreciated.
I think the tender was an SP prototype and previously made by Varney.? I've looked through several SP steam books and not yet found an SP Vanderbilt tender with Buckeye trucks.??
I plan to use my Buckeye trucks under another project (a resin N&W auxiliary tender from Funaro and Camarlengo), and I bought some Precision Scale Co. 3186.1 brass Commonweath trucks which look like they will fit, but I haven't tested them yet.