It's missing the connector and power components on the PCB so you may be able to solder them all on yourself if you have the parts but it's going to be a pain in the ass :D

Yeah; I attempted to solder on the slot... but realized after attempting it that all the power circuit components on the underside are also unpopulated. So you'd have to reverse-engineer that, get the components, solder all of them (many are tiny SMD), and solder on a couple caps on the top PCIe traces, and finally an M.2 slot on the pads up top.