Ken, a zero frame Parker with pin separation at one inch exactly is a very proper fit for 16, 20, and 28 gauge barrels. The thing that will make a one inch XX frame Lefever a bit slimmer looking than a zero frame 28 gauge Parker is the fact that the Lefever frame tapers in at the front more than the almost slab sided Parker frame does. Make sure your donor frame is an actual one inch pin separation frame. Our thread on the old Lefever forum uncovered the fact that some XX frames had firing pin separation of more than one inch, making the whole frame and barrel assembly more massive than it has to be. In my opinion, the one inch frame is to be preferred over any with a larger separation. Your barrel supplier should be able to make barrels in all three sizes as easily as for just two if the firing pin separation is the same for all three. In addition, some of your contributors seem to thing that a 26" barrel option made from cut 28" barrels has to have a separation between the barrels at the muzzle. That is not true, depending on the design of the barrel assembly. I have Parkers that are cut from 30" to 26" that have touching tubes at the muzzle. Zoli can make your barrel sets the same way if they won't make the three lengths at a reasonable price. My guess is that they will not charge you any more to offer a choice of three lengths than they would charge for just two choices. Yes, 26" should be offered, but so should the very popular 30".