Wheel size decoding help

I’m shopping for used wheels to use for winter tires. New wheels for the Volt in the stock size are more than I’m looking to spend. I didn’t find any used wheels that will fit.

Thankfully, I found some members of a Volt forum that run 16” wheels in winter.

I found some BBS wheels on Craigslist, and most of the specs I can decode seem like they’ll work.

So, I’m reading this as a 16” wheel that’s 8” wide with a 42mm offset. Can I determine the center bore based on the stamping?

Unfortunately, the seller took them off a car he bought used that already had them mounted. He didn’t have any information other than the bolt pattern listed and said that was all he knew.

Help me Oppo Wan Kenobis; you’re my only hope.