My humble opinion is for the cost of. New unit- buy it. After going thru removing the old one, new gasket and possibly a ring plus a sock and it may or may not work plus after treating it.. what do you do to protect it from this crap fuel. It will just rust / corrode up again in a very short time.
SN I love evaporust- it’s awesome for chains here on my farm. Soak and mix a few days rinse with water and dry and coat with an oil based paint. Look good for quite a while.