Use a cotton rag over your 8mm socket if you intend to remove the face plate.
In the case of hard to remove gunk, i use PB Blaster., with this warning...Use it as a last resort!
I have gotten warned about the penetrating spray product called PB Blaster possibly harming the lettering.
I personally had good results on quite a few plates, but that is not saying its not going to wipe the lettering off of yours.
So, if you decide to try it, use it with that warning. I have found it will take off nasty brown films on some plates and not on others. Most folks use dish soap and water, but never ever "rub" it or use a rough cloth over lettering, no matter what your using.
Who knows what the guy before you did to it, and if the lettering has been compromised, then you will ruin it.
Caution:
Do not use anything but soap and hot water and a gentle soft CLEAN cloth to clean the clear window, letting it air dry.
Just remember no mater what you use to clean you plate, remember to rinse it off good and let it air dry, using a soft towel if need be, but never use anything on the dial to dry it, unless it is a camera lens cloth or softer. Just looking at it will leave fine scratches and it will never be as nice as it was before it was touched. sorry for ranting on it, but i don't want you to learn the hard way like i had to.
john
On a side note,
I can vouch for Blue Shadow not meaning any harm here. The guy is a Top Shelf member that has helped me a Thousand times and has never posted a negative comment that i ever witnessed. Things are not always as they seem and we do our best to remove personal attacks and negative attitudes before posting.
That "No Attitude" is what separates and elevates Audiokarma above the low class trash found on the web.

