He's a nice one, but I'm afraid you did rather overpay for him.
The splodgy patterns were introduced by Joseph Said in the '80s, he's definitely post-Harris ('68 - '72).
Just enjoy him, we all make mistakes, it's how we learn, and the bottom line is you liked him and got your purse out. It's not the end of the world.
However, if you want to stick around and ask questions, you'll learn a whole load
about glass here - but be warned - it's addictive.