Looks like it'd be tough, since the mounting holes on the X52 are pretty far apart, and the arms of your chair are curved.
Off the top of my head, I'd just suggest mounting them both to plywood (or other wooden) boards, and just c-clamping them to the arms; you'd need to add spacers to compensate for the curve of the arms, but probably only one good clamp each. You'd likely severely damage the arms with clamping though.
You could build a fancy rig with hooks or bolts and hinges and stuff if you have the material/time/tools/skill.
Actually, if you mounted the HOTAS to boards, you could put mounting slots wherever you pleased on the boards, and directly bolt them to the arms, probably.