47-55.1 Cadillac El Dorado/Seville rear calipers with parking break leaking

[NeoJuice]

After finishing up changes on the brake system on the 52 I found some break fluid dripping down onto the garage floor. I pulled off the rear drivers side caliper off the GM 10 bolt rear and found fluid leaking out around the high lighted area the attached photos. The brake fluid is not coming out from the outside piston wall, its coming out of the hole in the middle. I pulled the little rubber stopper out cleaned everything up with brake clean and rags and its still leaking out at a decent drip rate. Since the calipers are a ratchet style with the built in ebrake Im assuming a seal must be leaking on the center hense the fluid loss. There is no fluid loss on the back side of the caplier where the ebrake lever is attached. I'm trying to figure out what my options are.

1. They are only covered under 1 year warranty from Napa. They were purchased about 3 years ago and the truck has yet to be driven. Maybe they would replace it under good will?
2. Shell out $154 CAD for a new caliper and replace it.
3. See if I can find a rebuild kit? might not be worth all the hassle?

Link for reference.

https://www.speedwaymotors.com/Emerg...pers,1968.html

Any thoughts would be appreciated.

Thank you.