To my limited knowledge there is no distinct 1897 Mauser action.
This may be a transition step between the earlier models (e.g. 93 Spanish or 96 Swedish) and the 98 action, maybe only made in small quantity and very interesting for a Mauser expert?

As to possible differences from the 98 model, there are plenty.
This is from Olson's book on the 98 model (Mauser Bolt Rifles, 3rd ed., 11th printing, 1993):

"Principal improvements over previous Mauser standard rifles produced in large quantity were cocking on opening of the bolt, shorter firing pin travel (only 1/2") and therefore faster lock time, extra large gas escape holes in the bolt, enlarged receiver ring for added strength at a vital point, locking screws to prevent the guard screws from vibrating loose, and a bolt sleeve lock. Also included were the full-deep thumb cut in the left wall of the receiver, guide rib on the bolt (first used in the Swedish Mauser), a safety lug, shrouded bolt head, gas shield on the bolt sleeve, and the undercut extractor (introduced with the German Model 96 experimental)."

Regards,
fuhrmann