I'm currently building two Ten Wheelers on the Bachmann chassis, using Varney boilers from their 4-6-0/2-8-0 and cabs from the Bachmann 2-8-0. I've also rebuilt the cylinder chest to represent one with piston valves. I used the stock tender (sorta), but sectioned-out some of its excess width - I'll need to fabricate new floors and frames.
Kevin, that Frisco loco isn't very far removed from the 1800s - it still has a wooden cab, single air pump and slide valves, along with archbar trucks under the tender.
The IHC is a pretty-good representation of a modernised Mogul and its tender can be easily shortened, altered, or swapped-out completely. I'm going to change the cab on both of my Moguls, using the Bachmann Consolidation cab as my road's "standard".
Here's IHC's Espee-style Mogul:
...and a PFM Boston & Maine B-15:
This is the Bachmann 4-6-0, pretty-well un-modified:
...and with the modified cylinder block:
Here's the boiler I plan to use:
...and after removing the cab and other extraneous details: