I've used Front Panel Express's design program to build a box for the RFPD. The attached PDF has 4 panels (front, back, top, bottom). The other two sides are fixed-width (42mm) side panels that are made by FPE. I have attached one page of their enclosure design manual so that you can get a rough idea of how it is put together.
The overall dimensions are 120 mm x 70 mm x 42 mm. All panels except for the bottom are 4 mm thick anodized blue, while the bottom is 1 cm thick (for rigidity) with natural finish.
The PCB that Alastair designed and has ordered will mount onto the front face of the box (where the PD will emerge from the bottom of the board), with the voltage regulator contacts mounting to the top of the box.
I am fairly sure that I've done it correctly, but the one thing I am not sure about is the SMA flange mount, which was not built in as a macro so I had to do it myself. In building it I realized that it is not really clear how we will connect the SMP ports on the board (for DC & RF Out) with the BNC and SMA outs on the back of the box. I assume that there are adapters for just this purpose, but we should double-check this before we put out the order.
As it stands now, the total quote (including the panels and hardware but not including the connector flanges which they don't sell) is $172. That seems a bit pricey, but we might be able to trim a little off by changing the design slightly. For example, they charge $10 for each of the panels on which they have to mill the bottom side. They have to do this for the front and back panels so that the edges fit into the side profiles. Presumably, the entire panel is anodized, so we can just have the edges milled out on the front side when we don't have to have anything written on it (like the front panel where the PD sticks through). All I would have to do is reposition the hole for the PD accordingly. Of course, the price goes down slightly if we order 5+.
Click on the picture to open the multi-page PDF.