Finally gave up finding one (unless I stumble across an antique/swap meet tool).



But, I did notice in the photo showing height measurement procedure (Classic Trucks series), they are using a spring seat shim stack (correct size still available) AND a smaller/shorter barrel mic., on bosses partially trimmed for PC seals (like mine). Adding the two measurements will get the job done.

6 VOLTS/POS. GRD. NW INDIANA