OK, we (LHS) were told by Weaver that their diecast Allied Full Cushion trucks WILL be available for separate sale. You will find them in a "Reserve It" category on their website.
After the troop cars left their product line-up a few years ago (no longer catalogued), the AFC trucks for separate sale also disappeared. I believe this is all intertwined with the miasma that occurred when Sanda Kan gave some of their 'lesser' accounts the boot, but I can't be sure of that.
Anyhow, when the troop cars returned to the Weaver catalog a few months ago, I called and asked if we could expect the return of the separate-sale AFC trucks. The answer was "Yes!". And, shortly thereafter, the part numbers P754 (2-rail) and P755 (3-rail) for the AFC trucks did, indeed, pop up on their list.
As with anything of this sort, we must be patient. I fully trust the Weaver folks. The trucks WILL come. BTW, though, we're only talking diecast metal trucks...no plastic for this type.
If you have ANY vision/projection for needing this unique style of truck (e.g., several roads put them under 40' and 50' boxcars for express service...ATSF, for one.) I wouldn't plan on these being available forever. If I were you, I'd order NOW to cover your present and future needs. That's what I've done, anyway. Besides, the good folks at Weaver would, I'm sure, appreciate knowing the most realistic size of their demand market on an item of this sort when scheduling a manufacturer half a world away.
FWIW, always...
KD