Looking for information on antique appraisals. Where do I go for an hosest answer for the worth of my items?

I live in Allentown Pa, and I have what I believe are a few antiques. I need to find out where I can go to get a real appraisal and not just someone trying to get my items off of me on the cheap. One item is something I've never seen before, it's a rectangular shaped wooden box, ont the top it has an engraved or burt in type stamp, it's dated pretty far back. The weird thing of this box is, when you open it, it doesn't open like a box would, it opens up FLAT and show a redish-purplish velvet lining.