I have finally worked out the magic formula to 3D print a female ECU connector using cheap and easily obtainable connectors. No more hording of the Bosch connectors. This connector is intended for diagnostic/temporary use rather than permanent installation.
The connector uses the TE 3-61668-1 (https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/3-61668-1/1981568) which are $0.16 for 25 of them at the time of writing.
The connector is available with and without a handle as it is a tight fit onto the edge connector of the ECU.
The STL files can be obtained from github here: https://github.com/ajayre/djetecuconnector/tree/main/Female