Jaguar pickguard on an sx bass

If I understand you correctly you're asking maybe a Fender jag pg on an SX jag? I'd say close but not a match. Same as other Fender/SX PGs like the P and J don't match up either. You'd be lucky to have the SX PG match an SX

 

Probably not without a lot of heartache. Besides the pickguards being different dimensions, the SX Jag body is a slightly different shape than the Fender Jag.

 

Slightly different bodies, sizes, and you would have the hole for controls on one side and a missing portion where more switches go on the other that the SX doesn't have. So it would look pretty weird.

 

Best bet is to make a template and have one made.