Cool picture and I really like his character design. As for his weapons, it would be more practical to use two normal revolvers with bayonet attachments. That way he can also use his pistols and knives separately and they are easier to store. If you keep the gunblades, I would shorten the actual barrel to about half its length, with the blade protuding to its full length below it - a longer barrel would slow down the bullet (rifles can afford it because they use stronger ammunition) and make the weapon more top-heavy, and the blade makes it top heavy enough as it is. It would only work with a comparably light blade, like a cutlass (where the blade is about as heavy as the handle - which would work well here as most of the metal is the pistol).
Cool picture and I really like his character design. As for his weapons, it would be more practical