A separate sale plastic or diecast 2426w style tender with handrails, steps, and 3 axle trucks.
You can buy these types of tenders at almost any show.
Dave
That has nothing to do with the question you posed in your original post. The 2426 tender is what I would like to see Menard's produce. Most of these tenders on eBay will sell from $150-200+ as a separate sale (granted the originals include a whistle). Granted you could probably find some cheaper at shows as you suggest, but I don't have time to go to shows. I'm suggesting that Menard's could have a market for these, especially if their price point was below $50. These empty tenders could house ERR upgrade boards, speakers (or a traditional air whistle) for conventional engines.
By the way, I don't see anything unique on your original list:
I would like to see buildings with a smaller foot print, backdrop buildings.
Freight cars I would like to see bulkhead flat cars, more single dome oil tank cars, 2 bay covered hoppers, modern box cars.
diecast vehicles from the 40's, 50's
You could find every one of your items at a show as well, nothing rare or un-produced there