I need a straight [shotgun] stack for a three-truck Shay

[tac]

I lucked into an unused Oregon Lumber three-truck Shay last week at a sale of unwanted trains.  Sadly, it has an onion stack and just looks wrong to me, it being oil-fired.

No help from Bachmann here in UK, so does anyone out there have one they could exchange mine for me, or even take $$$ instead?

tac
OVGRS
POCR