How can I find out if my antique item has any value?

ebay
get an appraisal
Antiques Roadshow!

Are there any antique dealers in your area?
You can always search ebay for a similar item.
I am a lover of Escher and would love to know more about the object you have. I will pull out my Escher books and see if I can identify it is you can provide more detail.

Things are worth what people are willing to pay for them, and if you are looking to sell them to a dealer, then expect to get roughly half of the estimated value.

I have a cover from a piece of 1927 sheet music that is reverse printed on glass in the manner that you describe. There is a technique for putting a print upside down on the glass and transferring certain types of ink to the glass. Does your piece have any indication of who the printer is? The value may lie in who created the print.

If you have an antiques auction house in town they will be able to give you an independent assessment there. Assessors at auction-houses will give you the true value, or maybe slightly over-value it, to encourage you to sell. An antiques dealer with a shop will under-value the item because he wants to buy it cheap and sell it at a profit. The true value would be somewhere inbetween these two values, possibly nearer to the auction-house one.

Another advantage of an auction-house is that they will have sales for specific categories of items. For instance your Escher picture would go in an art sale, the lightshade in a toys or memorabilia sale. This way, you’ll get buyers specifically interested in that kind of thing.

I’m not interested in selling. I like what I have. I’m just curious if they were worth anything, since I haven’t seen things similar to them. An appraisal would cost money. Even without learning the value (most likely 0), I’d like to learn the background of the Escher.

Try to put some pictures on here some one may recognise something