The following Baldwin filters appear to fit the adaptor base for the Ford Lehman 120 and SP 135.
Micron ratings as per Baldwin:
BF790-5 nominal, 20 absolute; 83.76% avg. efficiency
BF788-4 nominal, 15 absolute; 83.76% avg. efficiency
BF988-4 nominal, 20 absolute; 86.34% avg. efficiency...