I did this several years ago, following the photograph and commentary in the I-15bis research section on 'white 68' on the old site. After seeing the new I-15bis profiles here, I took some fresh pictures of it, using a light-box wife got me as a Valentine's Day present.
I missed the antenna wire, and suppose I ought to put it on sometime. I am glad to know the unit and use of the thing, surviving so late and out of the way as it did.
The kit is the old-tool ICM 1/72 kit, with a few tweaks. I lengthened the interplane struts to match the gap set by the kit cabanes. I think this makes the gap a hair too great, and that the best way to approach this kit is to extend the interplanes by 0.5mm, and scratch new cabanes to match. I assembled and finished the wings as a unit, and attached them then to the assembled and largely finished fuselage. This makes dealing with seams at the interplane to wing joints easier, and if you prepare with some care, the lower wing can fit quite nicely, even at the fuselage bottom. The open bottom allows for good placement of interior elements, too.