I think the outer solid component of Gecko pads, at least the fiberglass version of the aluminum Geckos, are riveted to the shanks. So if you could get them, I guess you maybe could mod them on the Bashlin shank. But although the soft portion of the Gecko pad is replaceable and available to buy, I'm not at all sure the solid portion would be...it's a fixed component of the gaff set, not meant to be replaced. But maybe, if one were to contact Gecko directly, who knows?
With the carbon fibre version, not happening...that's all of a piece, shank and pad outer together, iirc.