The Vincent Black Shadow is legendary and today, you'll pay a premium price for almost any example that comes up for sale, but many seem to forget, when new, these bikes were ridden hard and raced hard and responsible for speed records that stood for many years. Now, every one is carefully examined and traced back to the day it came from the factory, the keepers of the Vincent registry know where each one is or was and if a bike has a discrepancy of one number or another, it actually becomes an opportunity for a buyer to get a Vincent at less than top dollar. This is one of those bikes.
The seller says he purchased the bike 14 years ago and believes it was restored in England sometime in the '80s. The upgraded Amal concentric carbs have been cleaned and the bike runs and rides fine, though, having been in storage for some time, a thorough going over is recommended if any serious riding is planned.
If you're someone who would seriously consider the purchase of a Black Shadow like this one, you're most likely well able to do the necessary research to follow the paper trail and figure out what the problem numbers indicate and whether it's important to you. The video of this bike provided by the seller shows it sounds and runs strong, so if you want to ride a legend and park it in your garage, here's your chance. It's for sale on eBay.