My 1977 R100S has the same machined pad on the left front of the block. I stamped my initials on it as a discrete means of identifying my bike/engine if it were ever stolen.
Since you how Canada as your home, is your bike a Euro model? That might be the reason some have it and some done. My '78 R100/7 is a US model...no pad.
Interesting, though, that BMW would have two separate molds for the block, one with and one without the pad.
Kurt -- Forum Liaison ---> Resources and Links Thread <---
'78 R100/7 & '69 R69S & '52 R25/2
mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!