The 1/32 model rail scale is "1 gauge" which is 45mm wide track spacing. But, that's to represent western track gauge of 4'-8-1/2" (1.435m).
1 Gauge has been nearly extinct for a long time, only available by way of specialty mail-order; but, it has seen some resurgence lately.
This can actually work to a modeler's benefit, as instead of kits, much of the available items are pieces-parts. Wheels, truck parts, couplers and the--so adapting to the Soviet standard is a bit more straight-forward. You should be able to get just the rails, and set them on ties ("sleepers" in UK parlance) to the width desired.
Now, with the rail gauge issue, the Germans might well have installed another rail at the German national gauge so as to not need to stop and switch rolling stock.
All this before one wanders afield into the narrow gauges; which are sometimes used as field-expedients and in working around battle damage, too.