I'm new to watch collecting. I recently bought a secondhand watch on a repair shop around my area. I had it buffed to remove some of the scratches and make it look shiny. I want to know if they have replaced the original parts. I tried to search online but I cant find any picture of the dial code. Here are the details

Seiko 5 Automatic 21 Jewels
Dial code: 7S26-11L2 R2
Back case: 7S26-02E0 A4 KY
Strap: 3282-G-E
Reference number: missing (I think it was erased due to age)