G5 oil pressure relief valve

Just cleaning the sump out, so checked out the pressure relief valve, haynes manual shows ‘seating disc’ (item 18) above the spring. No sign of this, or of any possible shims, as are mentioned in the haynes text. Has anyone else noticed the absence of these?

No issues prior to removal, only way to check is with a pressure gauge i guess…

If I remember rightly MG manual says add or remove shims as necessary until correct pressure is achieved, about 80 psi. (?) Presume yours has a stronger spring then so all shims taken out.