I know this is an old thread, but I can't believe how similar our circumstances are and this gives me hope! There is a medical collection on my husband's report from 2011. Like you, I actually paid it off in full to the Medical Center a year and a half ago but the collection agency never knew. I contacted the collection agency and they wrote me a deletion letter that day. They were actually really nice and helpful! I gave it to our lender on Monday and he is working on a rapid rescore. His score is also in the 690s/670s and we need it to be over 700 to qualify for a jumbo loan.

My husband only has one credit card and his utilization was about 14%--I am paying it down to under 9%.

There was one late payment (because of an expired cc number that was set on auto-payment) but it has been changed from 30 days to 0 days past due by the car company. So, that is gone.

I hope we have the same success as you.