Gravely brake knob question

I have a Gravely 260 XDZ (model #992151, SN 00600).  My dog has chewed off the brake/steering lock knob, part #07505200.  Does anyone know the thread pitch of this knob?  I've looked but can't find that information.  I want to get a skull knob to replace it.  You know, just because!  I'll take suggestions on where to find cool custom mower parts as well.  Thanks!