I'd imagine that general interest probably wouldn't be great enough to warrant the factory designing and tooling up for such a guitar. Whilst superficially similar to an ES-3, that double cut-away and neck join are really very different. If the bodies are based on guitars the factory is fully assembling for other companies, then the cost of setting up a small side-line to make a different body and neck design just for the kit construction market, then it may simply be cost prohibitive.

For instance, the ES-3 cutaway has a constant radius curve, whilst to match the Barney Kessel model, the curve to heel join would either have to be bent at a much tighter radius at the join point, or else the curve and heel would need to be separate pieces of wood, with the danger of a very obvious join line. Bending at a tighter radius requires a lot more care and skill (and maybe a better quality of ply or using a different wood), and would probably result in a lot higher breakage rate. Whilst modifying the design to the extent I mentioned might put some people off.

To keep the correct overall shape, you could alter the design even more so that the large 'heel' was part of the neck rather than the body, and so move the join line way back near the end of the fretboard. This should allow you to keep a constant radius curve for the cutaways, but would create a real headache as to how to join the neck and body together. You'd need a very long tongue running inside the guitar for neck stability, but this would be very difficult to glue together without supplying some custom clamping jig parts as well (remember by extending the neck's heel, we have made it a very heavy neck to support).

If this pushed the cost up for the bare kit alone from around A$250 for the ES-3 to say A$450 in order to try and recoup design, tooling, retraining and longer construction times, then only the real die-hard BK lovers would buy the kit. Of course I'm simply guessing here at costs, but the kits do need to be relatively easy to make designs in order to sell them in bulk at affordable prices.