Yes, thank you. I'm sure you're right. This page shows what seems to be the same marking. I was confused by the long upper stroke which made the 1 look like a 7: https://stewartsmilitaryantiques.com/german-wwii-iron-cross-1st-class-marked-15-friedrich-orth.57640.archive.htm I'm getting a lot more hits search for Orth.
Given that it seems in very good condition, I imagine it would be towards the upper end of the price bracket?