Please upload some full pictures of the cassette when you can, I’d be curious to see the rest of it, since the seller only showed the front.
As for me, I’ve been on a buying binge of late. I don’t want to spoil the surprise, but I will tease one item that is being shipped to me currently. It is rare, it isn’t on this site, and it is the 3rd "version" out there and I wasn’t aware of it, until I was sent a picture of it and yelled "holy shit!" at my monitor.
Yes, I can hardly wait to see the rest myself, so I’ll share soon as it comes in! Very curious as well what you found!