I ended up going for my "true" size, 31. Thanks xcoldricex for handling my mid-transaction adjustment!
Based on the very good information here, and being limited to the relatively primitive wash machines at my local laundromat, I settled on a warm machine wash and hot dryer, taking the jeans out when still slightly damp in the fly placket (thickest part.) I was aiming to get the majority of shrinkage done without "overshooting" and ending up with a waist tourniquet.
All these pics are post wash.
The tag didn't suffer too much.
Gold selvage line.
An attempt to convey the texture; bobbly and hairy.
Front and rear pocket details:
Being worn. Sorry about my dirty mirror.
Thanks to all who helped. I am very satisfied with the jeans, and the fit. These are nice.