Thanks to all.
Shipwreck, the base is a 27-inch square piece of birch plywood, with a small moulding nailed to the sides to provide a edge so the acrylic cover could sit inside and not slide around. I stained the whole thing cherry, and puttied the small nail holes and mitre joints where the moulding came together in the corners. The acrylic cover was made by J-Display Cases and I highly recommend them for the quality of their work; but don't be in a hurry to get it! His email is <jdisplaycase@fuse.net>. They have been very helpful to me.
USAFASME7, thanks. I almost had the same reaction when I dropped it...it took me about three days before I could think coherently about it afterwards. My wife was concerned about my mental well-being for awhile. But I got over it and tried again. As you can see from the photo, my friend is not young and I did not have the luxury of wallowing around in self-pity for very long!
When I gave it to my friend yesterday, he went back in the back room and rummaged around for awhile, then brought out his own Distinguished Flying Cross medal in its original case from WWII. We've spent the last day and a half reliving memories from that airplane, and that has been worth the entire venture. The small picture in the display case is a photo take on Iwo Jima in June 1945 which shows that airplane sitting on the ground parked next to another. I discovered that photo by accident in my research, and my friend was not aware of its existence until I shared it with him. It adds a nice touch to the case.
Cheers, Bob