When a seller decides to use the word 'patina' in his or her description, the true definition should be sought in a proper dictionary! I have handled, and owned, countless guns with 'patina' that was nothing more than 100 years of rust build-up, polished smooth after decades of applications of oil and general use/handling.
Amen, regarding guns a trendy word for rust....... just like "the barrels only have one small dent" (that I can see or want to tell you about, hoping you are blind)......

.......and "it will never effect the guns shooting quality"......
Or how about:
"it looks like it should for a 100 year old gun" (that's been kept in a barn)