Hello - The top cover shows very minor signs of wear and was taken from a Arsenal SA M-7. It was constructed for milled receivers. I have two threaded muzzle brakes for sale, one was made by an unknown manufacturer and the second is manufactured by Tapco. Each item is 10.00 firm or I'll sell all three for 25.00 firm. I'm having trouble with uploading so please message me and I'll send a pic to your email address. Please let me know if you're interested. Thanks!