Today I was visiting in local gun shop. Usually there is nothing interesting for sale on finnish gun shops, but today my eye caught something. Longish sporterized Mauser with chopped stock and wooden handguard, floorplate leaver release and double set trigger. I asked if I could look it closer, since it was odd to see set trigger and floorplate release on military rifle. Also walnut looked to be too good for military purposes.
I was amazed. It was original Mauser Oberndorf Sporter from 1914.
Since it had quite long barrel and wooden handguard, I assumed it was "Africa" model. But since the stock was chopped and front sling swivel was attatched to the barrel (rather than stock, like on most Africa models), I was not sure. There was also hole or channel, like for a cleaning rod at end of stock (okay it might be just hollow channel under barrel that came visible after the stock was cut).
Caliber seamed to be quite small. Shopkeeper assumed 7x57, but was not sure. Maybe even 6,5 mm.

What was the barrel lenght on "Africa" model Mausers and was there other sporter models with handguards?
Should I offer something or let it be, since it was chopped and full of surface rust?