In the larger scales, and also smaller ones- most
'Fireless Cooker' models were offered as pricy, fabricated
brass, limited run units.
However, there are diecast and molded plastic mass produced
0-6-0 and 0-8-0 copies of European (and export) prototypes,
that easily adapt to some North American units.
Some are available for under two hundred bucks complete.
They are in 'HO', 'N' and 'TT' from ROCO, TRIX/MÆRKLIN,
and others (including I believe Parts of the BACHMANN
cartel). So looking in their catalogs, or at online dealers
(e.g. MICRO MACRO MUNDO;REYNAULD'S EURO- IMPORTS;
MODELLBAHN OTT; E-R MODEL IMPORTERS; EURO RAIL
HOBBIES) or direct from European dealers, you can find them.
If you are an E-Bay devotee, look on the German E-Bay
for bargain priced used versions, and so forth.
In any event , many past and present good performing
models are there to be gotten for fodder for the person
wishing to have a scale model of 'Fireless Cooker.'
Good-Luck, PJB