Well, I wanted to add ethernet to the sled on the boat, so it was time to make another ethernet adapter. I decided to try clear acrylic. I got a remnant piece of 1/2" acrylic from a local plastics shop for $2 and made one (ethernet-only) and liked it enough that I made a 2nd ethernet/power adapter for my in-progress home dock #2. I added 2 pics on riocar.org: here and here.

The big advantage of the acrylic is that I could screw it to the sled, insert the Empeg, and then use a marker to draw cross-hairs for ethernet/power hole drilling. I used a 3/8" forster bit to drill each of those and then expanded/shaped with a dremel. I also used the forster to countersink some indents for the rear mounting bolt and to make sure the acrylic cleared the DB9 connector. I used 3 1/2" #10 sheet metal screws to secure the acrylic. The acrylic is pretty brittle, so I had to drill holes for those screws that were almost as big as the screws themselves, otherwise it would start to shatter as you turned the screws in. I think Lexan-type acrylic is a little less brittle, so if you could find a scrap of that, it might be easier to work with.

I followed Tony's example with hot-melt glue. It doesn't adhere too well to the acrylic, but by building a lot of it up on the backside of the sled, it seems to hold the two plugs pretty firmly. I just had to work fast to get it on there and positioned initially (with Empeg inserted) before it cooled, then I built up more on the back..