Quick question for everyone...do you think some dents in the grill from stick hits on mics like a 421 will affect it's sound or performance? I'm looking to purchase a few 421's, and I've found some used, but they do have some dents here and there from stick hits. The owner claims they work fine and such. These are mid-80's to early 90's models I think (any difference in them and the new ones)? Thanks!