Your overall limit is $6750 plus $1000 for you plus $1000 for him. There is no "all three" loophole. (If you are HSA eligible, you can have as many separate accounts as you want, 2, 3 or 50, but the overall contribution limit is the same.)
If your husband has qualifying family insurance, then both HSAs are considered family HSAs, but they share the overall annual maximums.
Anything that you or your husband contribute out of pocket is tax deductible on your tax return as long as you keep to the individual and overall limits. You each have an individual limit of $7750, and a family overall limit of $8750.
