Bosch had a family of mechanical fuel injection systems for gas engines from the late 60s through mid 80s, the Bosch CIS. It was used as the basis for a later electronic injection system, CIS-E. The non-electronic one is common on VWs from the 70s through about 1984, and was also licensed out to lots of other car makers like Toyota.
I imagine a mechanically inclined sort could make these work with lots of different engines.