Amon Amarth - Twilight Of The... Vinyl-question

Usually, a double LP has wider grooves, for better sound quality, and are played on 45 RPM.
I have this set, but still sealed, will keep it that way for some time I think (or maybe buy a 2nd set to open :p )

BTW, my set has no number on th outside, is it on a certificate inside or something?
 
But serious, where's the number supposed to be??

EDIT: there seem to be multiple versions:
- a picture disc, 500 copies
- 2 LP set, unnumbered
- 2 LP set, 2000 copies
- 2 LP set, 1500 copies

I've sent some mails around, I hope to recieve some answers soon, I'll post them here and in the Catalogue topic.
 
I have # 1499. I have played it. I also took the poster out to get it framed but haven't found a good frame. To those who don't play their copy, I can see why. But just remember, even if it's worth 1,000 dollars in 30 years you made like, 10 cents a day. Big deal.