What a great memory and keepsake! I hope you still have the album! 

My experience with the Monster Mash is very different. I was about 5 or 6 years old when it came out and it was the very first record I ever owned. Back then, 45's were only 69 cents each at your local record or department store and that's what I wanted for my birthday that year. I got it and played the thing so much, I practically wore out the grooves. Somehow, after all these years, I still have it on the old Garpax (short for Gary Paxton) label. 

I can honestly say it remains the only novelty record I can listen to over and over again. Most wear out their welcome after a few spins. The Monster Mash never seems to, which may be why it's stood the test of time for so long. 

You make a very good point, Karen. I did some searching and found that the Beach Boys did back Pickett early on (there's a picture of them doing so at https://tinyurl.com/y647t83f). But as for Van Halen, I wonder if he might have backed Pickett after the song became a hit again in 1973. I found a reference to both the Beach Boys and Van Halen doing this at https://www.billboard.com/articles/columns/rock/8015114/monster-mash-bobby-boris-pickett-halloween-history, and it refers to Pickett having used them as backing musicians "throughout the years". I think that the fact that the Beach Boys did so when it was originally a hit has led to the NME writer conflating the two, and I can see how that could more easily happen because of the unusual situation of the song having become a big hit twice.