Hi. I have a used Colt MPC marked bolt for sale. It was sold to me in like new condition (but I can't be 100% sure of that), and I fired 100 or so rounds with it in my retro clone before replacing it with a more period correct chrome bolt. The price is $35 shipped paid via PayPal (+4% fee, or use the gift option and there's no fee). If interested, please post an "I'll take it" here followed by an IM. Thanks.