sunroof failure

Hello. Sorry - this newbie mistakenly posted this in the Gen 4 forum earlier today...

We have a 2015 Prius with about 135K miles. It's been a fantastic little car. Since last year, it has mostly been driven by our teenage son, only about 3 miles to/from work and college. The car has no mechanical issues and drives great. It gets all regularly scheduled maintenance at the Toyota dealership about 35 miles down the road from where we live. Same place we purchased it in 2015.

About a month ago, we came out and see that the gasket around the sunroof is bulging out in random spots. There is some obvious sun damage on parts too (see photos). We are not seeing or feeling any obvious water, but there is clearly more humidity in the car than normal. The floor mats also have water -- but it is winter here and there is disagreement as to if the water on the front floor mats is from snow/wet boots or the sunroof issue.

We're afraid to open the sunroof to try and fix it because we're concerned we won't be able to close it again and perhaps make the leaking worse.

I called our local glass/window shop and they said they don't do anything with sunroofs and suggested it's probably just clogged.

I decided to take it to the dealership and after $90 diagnosis fee, they quoted us $4100 plus tax to repair this. They explained that they cannot ONLY replace the gasket, but the entire two-piece glass panel also needs replacing -- they claim that they cannot get the gasket without the glass. Needless to say, we are looking for alternatives.

Option 1: Seal it shut -- this was suggested by the guy at our dealership who signed me out today. He referred me to a glass place that apparently does this. I called them and they say they can look at it, but cannot say if it's feasible to seal it before they see it in person. We would commit to driving this car until it dies if we go this route.

Option 2: Sell/trade-in for another car (without a sunroof). Eat the $4k if we go thru dealership of course. The dealer offered $3200 at best on trade-in.

Option 3: Try to repair it ourselves -- this makes me incredibly nervous and it sounds practically impossible to even find the damn gasket part number from our limited online research. AND we are not mechanical folks. My dad, rest is soul, being an old school mechanic, would be disappointed I even bought a hybrid but we are who we are.

I appreciate any advice you can offer. Kathy in WA