You need the services of a professional firearms appraiser
would you believe in 1887- in Mexico? Patented by Gen. Mondragon, the rifle was in caliber 7mm Mauser, and capable of semi or fully automatic fire.http://en.wikipedia.org/wiki/Mondrag%C3%B3n_rifle
I would contact Walther directly and ask for a parts drawing. See the link below
Some guns yes, but most guns would require gunsmithing to change caliber.
That would depend on the caliber, the distance you are shootingt and your location.
Many would say the 22 Long Rifle.
That would depend on the caliber, and type of bullet, the rifle uses.
If properly trained, no
.22 caliber rifle.
270
Question to general. With info given I would have to give a poor rating to the gun and a value of 125.00 Gene61
Would need more info on the rifle, caliber, model, condition and images would be nice
Some would say Anschutz, others would say Remington, others would say Walther.