NOT 100% certain if this is from a 527 action. Could well be for a rim fire. Certainly would not accommodate a 550 model. I will try a reasonably modern 527 barrel and action into this as soon as one comes in as well as a rim fire. If you need a replacement / are looking then the image of the inlet SHOULD tell you yes or no. We can always actually try it too.
A Well Patterned and Quite Decorative Walnut stock with a Heavy / Varmint / Target weight barrel profile cut out.
Basically Brand New Condition.