Hi All. I'll post pictures when it arrives!

The nitro proof mark was on the side of the barrels, not the flats, best seen in the pictures showing the sides of the receiver. The "N" is to the left of the "2.7 g G.B.R" over St m G (Stahl Mantel Geschoss or Steel Jacked Bullet). This is different than the mark for copper jacketed bullets, K m G for Kupfermantelgeschoss.

Kuduae, does this sound correct re steel vs copper jackets?

I am hoping for either 9.3x72r or 9.3x74r.

I was initially confused by the 118/35 stamp, thinking it was an odd date stamp (118 days into 1935?) but then read more about gauge markings. Wikipedia has the formula for converting gauge into bore (https://en.wikipedia.org/wiki/Gauge_(firearms)) 118/35 translates into 0.340 bore diameter (not groove diameter.)

I am glad to hear this was proofed pre-1912 as the engraving had an Art Nouveau feel to it and that period ended pre WW1.

There is currently a newer pre-WW2 Weisgerber-retailed Merkel double on Guns International. Nicer than the rifle we're discussing. Has been for sale there since 2018. (https://www.gunsinternational.com/guns-for-sale-online/rifles/merkel-rifles/merkel-model-132-pre-ww2-double-rifle-8-x-57-jr.cfm?gun_id=101787360) Beautiful but $10,000 more than the rifle I just won.

This was an unusually hasty decision for me as I didn't see the listing to the day before it closed. Hopefully I won't regret it.

Regards,
Chris