Which pads for unknown calipers?

[Muckroot]

I have a caliper assembly that fits the 34mm forks I'm running on my hardtail project. I cant figure out which pads to get from mikes though, because two of the options have key tabs on them. can anyone eyeball this caliper and let me know which of these two sets of pads is the correct set?

https://www.mikesxs.net/yamaha-xs65...06-25811-05-1a1-w0045-00-1a1-w0045-00-00.html
https://www.mikesxs.net/yamaha-xs650-brake-pad-set-2-xs2-tx650a-round-oem-1a1-w0045-00.html

Also, in the pictures I've already blasted the calipers with baking soda as best I could. Do they look like they'll run safely with a fresh set of seals? Also, should I pony up the 40$ to buy new pistons for this caliper? if so, is this the correct piston?
https://www.mikesxs.net/yamaha-xs650-caliper-piston-all-fronts-1972-76.html

Thank you all for enduring my endless noob questions;
Best, Muckroot

Edit: forgot to add the pictures

 

[XsJosh]

Those are calipers take stock 75' pads I know because that's what I used in them. I think the pistons will be fine with a little clean up with fine Emery cloth and some new seals. The corrosion on the inside of the pistons does not matter it's the outside where the seals ride that you have to worry about.