Just looking something up today and ran across this. Thought I'd share. Some of these people that do "restoration" work are pretty good at their craft.
In the 16th-19th centuries ancient statues and vases were restored this way. When you look at famous Greek statues in the Louvre or the Vatican museums, it's hard to tell which parts are original and which ones are 17th c. restorations...
It is extraordinary good work and if I discovered I had bought this it wouldn't concern me unless it was sold in a deceptive manner. We fully accept restored paintings as preservation and to extend longevity so why not coins if openly presented. If this was being graded I hope the owner isn't disappointed with a "details plugged" grade. I bought a scarce plugged hammered siege coin once because the alternative would have been four times the price. Thank you for sharing.
They clearly damaged the original details here. This practice is absolutely unacceptable. Not just plugging the hole, that would not be a problem by itself, but letters, fields and some details were 'improved'. Compare with these two coins from my collection. Same dies, one with plugged hole. The plug is of different color, no other enhancements.