1900 extra part?

[dieNusse1]

I have a 1910 production 1900 KED 12 ga. (Q383xxx) that appears to have an extra part. The other item of note is that it is has the narrow action body (~ 1.5+" across the water table which is ~1/8" narrower than my other 1900s & 1894s). The part fits on the hammer pivot pin between the hammers. It roughly diamond shaped and measures 0.364" x 0.461" and is 0.341" wide. It is well finished appears to be original to the gun. It doesn't appear on any of the period parts listings. The purpose is unknown - a spacer or perhaps to keep dirt out of the action??? I ran this by Charles Semmer some time ago but he had not seen or heard of such a part. Any input from the group?