Boutique guitar amp is such a silly term, and nowadays, most "boutique amps" are made in China, and private labeled, since they are just copies of old Marshall and Fender amps. Take a look around the shop, it's just Bob and Jimi, building Bob's original design amps (and now a couple of pedals, too) on his work benches. These are guitar amps for great players, not copies of old designs. Also, you will not find them in any stores! Where is boutique guitar amps store? I think it's called guitar center. You won't find these there.
Bob discusses his amp building history. Please do not ask him to build one of his old products. He is only building his current products.