Here’s another one that has been hiding from me in a spot I’ve traveled often enough. I think I can see why: it’s quite worn and probably visible only in good light. It’s on the east side of Lathrop Street, south of Elizabeth.
I have only found one other stamp by this contractor, so this is a rare one. XMC is, by my best guess, short for <guitar-lick>Xtreme Mason Contractors</guitar-lick>, a contractor from Laingsburg. The last digit of the date is a little uncertain but my best guess is that it’s a 2.