Imperial P 08 Weimar re-issue, Cavalry marked

[DonVoigt]

I recently found this 1917 Artillery with 4" barrel with Weimar eagle proof installed.

Best of all it is marked to a "Reiter Regiment"; :
marked A./R.R. 15.3., Ausbildungs 15th Reiter Regiment weapon 3.

In nice shape, frame and receiver appear in original blue, replacement barrel is in noticeably different color.

All matching, including grips. Beech bottom unmarked magazine.
Has the 1932 grooving upgrade to the striker, and rear toggle pin numbered.

It has a marking I have not seen on the rear toggle,
Crown/script B(?) over W, above the normal part number.

Wurttenburg ownership? Anyone?

Thanks for looking.