Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Nick has already supplied you with the important pieces of information.

Doll stacks are not that rare, on German ebay you will find them offered once in a while (but the shipping cost and fees might be prohibitive).

Bending the water gauge glasses is really not that tricky - theoretically... Sometimes you really get the creeps when another perfectly looking glass does not fit by fractions of a millimeter (no, don't try to re-heat, they will inevitably burst at the bends...). If you need it, there will probably be a tutorial here in the forum somewhere.
Regarding the seals: I do recommend slices of (soft) silicone-tube. You can easily adapt the size and they fit perfectly.
The sight-glass covers came in different shapes, according to date of delivery and size...

This Doll ship's engine is not a rare specimen, but a very nice item and usually a good runner (perhaps running a bit roughly, as the two pistons work on the same crank and "fire" at the same time, due to their shared valve).

Good luck with the restoration!
And here another original burner, a vaporizer with three domes, this time. Size depends on the size of the engine:
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I can supply you with the necessary measurements and details, of course - but a simple tray with fuel tablets will do the trick as well...(but alcohol burners are much nicer)