I need to find a replacement faceplate for a jbl MR-6.2

Question edited for clarity, proper 'make model (what it is)'.

I can't find a manual, but they have a common theme. Remove the faceplate and press the Reset Button, then clean the contacts both sides with electrical switch cleaner or Isopropyl Alcohol.

https://www.premiumleisure.com/Manuals/nov07/Hydro_Spa_JBL_Stereo.pdf

https://www.rocktheboatmarinestereo.com/specs/MR18.pdf

https://www.google.com/search?q=JBL+marine+MR-15b+manual

..

try a wreckers as they salvage a range of radios.

See page 2 of this manual:
http://www.prospecelectronics.com/manuals/JBL%20MR5%20manual.pdf

Because of that moisture it may have fired the lighting connection inside the unit, does it produce and sound?

You will find the maual you need by using the following link :

http://www.prospecelectronics.com/JBL%20MR6%20manual.pdf

I have the exact same issue. I have swapped with two identical MR17.2 radios and swapped out the sirius receiver. No change. I even bought a remote thinking I had to have a remote installed to get it to work...still no diff. Have you ever found a solution?

you can make one to fit where you want

I have looked at several sites and none say that they do so I assume they don't.Also if a player does it normally says on the front.

try ebay, or amazon

As for JBL is a band name.
http://www.jblproservice.com/
Hope this answers your question.
Mike