CL360 seat issue with photos (and looking for a source for old?)

[papercrate]

Picked up a half-finished project bike (1974 CL360) later last year and just digging into it now. It looks like the stay bolt for the tank was missing and maybe a bracket or clamp for the seat that should maybe be there? The seat wasn't original and didn't fit on the bike, I've also somehow replaced it in the last 12 months. Anyways, was hoping somebody could post some images or a short video on how their CL (or matching/equivalent) seat sits on the bike/attaches so I can discern just how modified this bike is and what it'll take to get a seat to fit on it. I was wondering if similar era CB and CL seats are interchangeable as well?

On that note, I've found a few old beat up original seats on eBay but the shipping cost is pretty outrageous so if anyone has any leads on where to pick up a used seat for this bike that'd be great!