I too received my pup very young (although some older pups just naturally have more of a biting tendency too). After two weeks of working on it, ZoE now has great bite inhibition. She "mouthed" my hand from the very beginning and as long as it was soft, I was ok with it, but as soon as she started to exert too much pressure with her teeth, I would yelp loudly & immediately stop playing with her and ignore for for about 30 seconds. Then I'd play with her again, giving her toys that she could bite, but as soon as she moved to my fingers, arms, whatever.... and exerted too much pressure (biting), then I'd repeat the yelping & ignoring. I did this over & over again each time we played. At the beginning of the second week, as soon as I'd yelp, she'd immediately stop biting & start licking me. After a full two weeks, she doesn't bite me at all any more
But be sure that you do provide Benji with things he can bite, chew & tug on. ZoE loves a long old sock tied in a knot, her stuffed bear & her nylabone blue nubby gel bone.