I open my HP Prodesk mini to install an Intel PCIe wifi / bluetooth card & the system has no screws / spacer in place to mount. Nor for an M.2 SSD. I looked through the service manual. I have searched the HP store, this forum and Googled it. The hardware reference pdf makes no spec to the screw / spacer size. Please can someone tell me the specification / size so I may search eBay. Thank you so much. Adam