Here are photos of the seat and the mount. And yes, that is a bent nail the prior owner was using as some sort of mount stop. Sheesh! I am glad I found that before I rode it much. I am not looking forward to singing soprano! I will flip the seat so it sits higher and make sure it is mounted correctly. And I agree with what I have read so far, this seems to be some kind of "bobber" El Tigre.