Arrieta usually maintained a number designation for their sidelocks.
The lowest grade, Model 557 the engraving is fine scroll.
Next is the 570, with broader scroll and side clips.
Next up is the 578, which resembles a Purdey with fine English style engraving.
Next is the 601, with a coin finish locks and no engraving except the bordes on the locks.
Next is the 801 with Churchill style engraving or tight small scroll, the 802 with Holland & Holland style and the 803 with Purdey style.
Next is the 873, has deep relief style game scenes engraving.
Next is the 874, no engraving but has fine borders of inlaid gold wire.
The top of the line Arrieta is the 875 which has deep scroll with game scenes and banners inlaid with gold.
The model Orvis imported the most were the 570 and 578.
I love my Arrieta, would I shoot trap with it every Saturday blasting hundreds and hundreds of rounds through, No!!! but to hunt with it, Yes!! Because for the money I don't think any maker can regulate barrels and chokes as good as the Spaniards can!!
