I just inherited one of these that was displayed only, do you have an idea what it's worth? I'm into standard G scale.
I just logged in after a very long absence and I have been notified of this three months old question you asked. These Shays sell for around 800 USD, or at least they used to some 10 years ago. But of course, you may get more if you are lucky, the price of brass knows no limits;-)...
If the loco and the box are in very good condition I may actually consider it myself, although I would need to find a good reason for having two of them;-)...
These are very cute engines even if very simple indeed. Since they are exactly 1:22.5 they do not appeal to the 1:20 crowd, nor to 1:24 people (if any of these still exist...).
Best wishes from Indoors,