Is this your primary source of income? If it is, you should be able to justify the expense of renting a dedicated business/shop space. If it isn't, then it's just a hobby, even if it provides you with some extra income.
Sorry if it sounds harsh, but it's true, and Milt nailed it with his earlier comments.
BTW, I operate a small home based business (hobby) that makes niche products. When I thought about taking it full time a few years ago, I ran the numbers, and included such things as rent, health insurance, taxes, and general overhead. The numbers were not in my favor, so I kept it home based, and kept my day job.
Good luck. (Do you make pickups for basses, as well?
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