Scratched BP SX420J 20W panel back--What to do? See pic and datasheet.

[ConcernedSeller]

I'm brand new here, so sorry if I go against any rules, regs, or norms.
That aside, I'm planning to sell a 11 year old BP (the fact it's made by an oil company feels wrong, but I digress) 20w panel I got for a steal (cl/ebay) and noticed a few dings on the backsheet. All but one are surface.
One is a bit concerning. It's a bit more than a scratch. A photo, with a quarter-watt resistor for scale.

Anyways, how should I cover the ding? Also, how much can I expect to get for the panel?

Fine. You can have the datasheet too. (Also for peeps on syr-c-h eng1n3s to discover). BP SX420J Datasheet

 

[Solar Guppy]

You can buy new 20 watt panels for $17 on amazon for reference

 

[ConcernedSeller]

Lol fair, although this guy isn't Chinesium. It has a aluminum frame an' whatnot. Still, what'ya think about repair?

 

[crossy]

If the scratch didn't go right through the plastic backing, I think it will be just fine.

Not that an 11 year old panel is going to be worth very much.

 

[timselectric]

Elastomer paint

 

[ConcernedSeller]

Lol I only need like 2 in^2. Would duct tape work?

 

[timselectric]

Just use some silicone.

 

[ConcernedSeller]

Ah thx. I have some of that somewhere.