Someone (Ben Zotto) is running a Kickstarter campaign for a history book on Sphere Corporation, the Utah company which shipped the M6800-based Sphere 1 computer in 1975. I have no links to the project or creator so I obviously can’t give any guarantees, but Zotto’s work on Sphere so far at https://sphere.computer, including a Sphere 1 emulator, looks impressive so I’d say this is a pretty good bet. One of the Kickstarter reward levels includes a PCB which Zotto himself designed for his 64K RAM expansion for the Sphere 1 (this one is US-only unfortunately). (The book is to be called Go Computer Now!; after all, why not?) There’s a bit over a day left in the Kickstarter, which has already reached 100%. Sean Haas recently interviewed Zotto about Sphere and the Kickstarter.