I'm kinda surprised that this ballast is still alive.
But the older stuff was almost always built to last anyways (It's called conservative design, folks. )
But there is one major safety flaw that no one's mentioned yet...lack of thermal protection built in. (Not "P" rated.)
There are not too many smells as rank and putrid as a burning ballast. Think stinky tennis shoes, mouldy fish and hot tar and it'll be close.
And in a few cases such ballasts have caused serious fires.
I have seen a few "P" rated ballasts still get hot enough to expel the tar-like potting compound inside, though.