i guess a shoulder bolt would do basically the same exact thing that the NV4500 spacers do, since there's nothing under the shift body. could you make a little spacer around the bolts, under the shifter body? thin tube that lets you torque the bolts and body against them and still slightly compress the gasket? should stabilize the shifter and still seal well.
i'm a huge fan of a tight shifter, none of that sloppy rubber isolated stuff.
this is an NV4500 shifter ...
