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

Silly me, a little Googling and a email to weedensteam.com gets me the model, its a Weeden No. 60.  The site, ran by a fellow named Frank, has parts for the sight glass though not the correct shape.  But perhaps we can build up the lower fitting to get a glass tube in while looking for a donor (or someone here has spares!).

Nice little Weeden site and I can even get a No. 14 Burner from him.