Option:
#B. You can try cleaning a used vacuum pump valve, and swap it out.

#1. Drain engine oil
#2. Remove the lower oil pan
#3. Remove the air cleaner oil accumulator drain tube for tank cleaning
#4. Remove the check valve retainer, and check valve
#5. Ream out the upper oil pan nipple that attaches to the air cleaner oil accumulator drain tube
#6. Replace the O-ring on the upper oil pan nipple where it attaches to the air cleaner oil accumulator drain tube
#7. Install the USED check valve and check valve retainer
#8. Install the CLEANED air cleaner oil accumulator drain tube
#9. Install the lower oil pan
#10. Install the NEW engine oil...