Plates

Below is a list of HHKB plate files that I have used for different keyboard build projects.

Notes

Each plate is for an HHKB-style layout, including: split right shift, split backspace, and blocked bottom corners (even for tray mount designs, so they'll be blocked solely by the plate themselves, not by any top case).
Unless otherwise specified, plates will: have a 1u-1.5u-7u-1.5u-1u bottom row; use MX PCB-mount stabilizer cutouts; and exclude center- and spacebar-position screwholes (specifically for tray-mount plates).
For MX, you'll want to get these cut in materials that are around 1.5mm thick. For Alps, it's recommended to cut these in materials between 1.0mm to 1.2mm thick (but I have personally gone down as low as 0.8mm and retaining backing layers).
I use Ponoko to cut plates. They (as with any other service) won't necessarily provide every material in every thickness. These files are all in SVG format, which upload rather quickly to their application (compared to DXF).
Generally, I'll use softer materials for higher kerf values (e.g. 0.2mm), and harder materials for lower values (e.g. 0.15mm), but your mileage may vary. I have only included one kerf variation for each plate.

Plates

Plate	Kerf	Notes
Sirius Alps	0.2mm	For Project Keyboard's Sirius. I have had this cut in POM and in leather.
J-02 Alps	0.15mm	For proto[Typist]'s J-02. I have had this cut in aluminum.
PH60 Alps	0.15mm	For DeskDaily's PH60. I have had this cut in aluminum. Not public - send me a message for more information.
Tray Alps [6.25u]	0.15mm	For tray mount 60% keyboards with a "standard" 6.25u bottom row (1.25u-1.25u-6.25u-1.25u-1.25u; would recommend cutting or engraving a design on the bottom-right corner blocker, which is twice as large as the left). I have had an older iteration of this cut in POM, plywood, and aluminum.
Tray Alps [6.5u AEK II]	0.15mm	For tray-mount 60% keyboards with AEK II bottom row (1.25u-1.5u-6.5u-1.5u-1.25u) and M0116 modifiers (for split backspace and split right shift). Alps plate-mount stabilizers (to match the keycaps), tray spacebar screwhole. I have had this cut in aluminum.
Tray Alps [7u]	0.2mm	For tray mount 60% keyboards. "Cool S" cutout designs near spacebar. I have had this cut in plywood and in a matboard.
Tray MX [7u]	0.2mm	For tray mount 60% keyboards. "Cool S" cutout designs near spacebar. I have this cut in acrylic and in a wood fiber taskboard.