The mag release button had a horizontal line pattern on it, as opposed to the round line sample identified on The existing kinds, see the picture underneath for an example: Regrettably, I'm on journey so I can't submit pics from the bolt. It is MPC engraved. The one marking over https://coltcombatelitecommander402265.bloggactivo.com/30731203/the-best-side-of-colt-python-6-for-sale