Hello- My computer has some problems and couldn't see what you did but thought I would put my suggestion on here since it fits the topic.
I needed sample glass and saw a guy who was working for a major company here and asked him if he might have a windshield that he replaced that wasn't in real bad shape and he had one. I told him I wanted it to practice repairs on and he even made some bulleyes, pits, etc. on it for me and said that's how he learned.
We got a good laugh cause he was used to people wanting their windshields new instead of doing more damage to them. I'm looking forward to practicing on it. Karen

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