the ID plate on our truck is pretty oxidized - and it has a bit of sealer on it from the previous owner rolling something on it (POR15?) to seal it from getting rustier. What is the best route to go about cleaning this w/o taking off the original lettering too much? I'd like to get that sealer off the bottom part and hopefully be able to read the rest of it a bit better. No looking for perfect, just better..... (I edited out the chassis no. since this is on my public flickr)