Rem700 Mcmillan stock how to extend 3/8"?

[yocan]

I have a rem700 done up by Weber customs, the combination of optic/gun/orangutan arms I need to get a 3/8" to get a full sight picture.

It has an decelerator pad on it (~4.5" on the buttstock 5" pad) I don't know which Mcmillan stock it is. So hoping someone on here knows enough from the 2 pics to go "get this" or at least tell me what to look up.

 

[Maxduty]

Rifle Parts for Rifle Repair by Gunsmiths or DIY Modifications | Brownells

Shop rifle parts (2,670) at Brownells, including barrels, stocks, triggers, and bolt carriers to customize, repair, or upgrade your rifle’s performance.

www.brownells.com

 

[camocorvette]

Kick Eez Stock Spacer 1/2 Black

These spacers are made from a strong lightweight plastic polymer that are easy to fit, grind and finish. The extra long slotted hole at the toe of the...

www.midwayusa.com