I think the Sternkreuz L325 refers to an L-form gasket. I remember looking them up at one time and found all the specs on them. I believe the L gasket is a little thicker than the I form gasket.
This particular gasket is available here: LG 325 CousinsUK does a better job of providing specifications on parts. A quick look there may provide more information.
This particular gasket is available here: LG 325 CousinsUK does a better job of providing specifications on parts. A quick look there may provide more information.