My SS statements show that I have earned 31 credits. I went to the SS office to verify, and they say I have earned 36 credits. I asked which information would be used to determine eligibility and they said the information at their office would be used. I mentioned this to a friend of mine and he said it might be worth my while to get SS to reconcile my statement to what SS shows on their computers when I go the office. I earn non SS income and am aware of the WEP. I am considering working some more with SS covered employment in order to take my SS benefit. It seems that the discrepancy might come from my pre-1978 wages. For example, in 1978, I earned $80. It's possible that I straddled the 2 quarters earning $40 in each of two quarters, therefore not earning any credits for that year. I doubt I still have those paychecks! Lol.
The Social Security statements that you receive online or by mail are informational only. Your official earnings record, including a record of your quarters of coverage, is on a database maintained by Social Security. It sounds like Social Security says that you have more quarters than your statements indicate, which is a good thing for you. I don't think you need to worry about the discrepancy unless you believe that you had earnings that aren't posted to your record.
You may want to consider using the maximization software available on this website in order to determine how much you are likely to receive if you accumulate 40 quarters of coverage. The software allows you to enter projected future earnings so that you can determine their effect on your potential benefit rate. The software is also programmed to handle the effects of WEP (https://www.ssa.gov/pubs/EN-05-10045.pdf).