Mr.Austin,

No, this is not the R.A. harness.

Clarence H.Mackay purchased the harness in the R.A. ( II.186) in 1925, at this time he had employed full time the services of probably the finest armourer of his generation, Daniel Tachaux. So had this been the R.A . piece, Tachaux would most certainly have restored the missing item while he was emplyed by Mackay.
In any event, if you look very closely you will see that the piece you show, though undoubtedly one of the twelve electoral armours, is not the R.A .one. The decoration on the couters and the top of the pauldron is a little different.

Regards,

Russ

Mr.Austin,

As you are especially interested in the Peffenhauser armour as you said, I wondered of you had read this article on Anton Peffenhauser...........

http://www.myArmoury.com/feature_arm_paffenhauser.html

Regards,

Russ