Mike, it was a 3000 Mark I with the horizontal wavy grille bars.
I was a schoolboy, too, when it was made. I first owned it ten years later. $500 was a lot of money at the time, to me, but they seem to have appreciated since then about 100 times, which puts it well above inflation. I of course sold it for less than I bought it for two years later, and bought another Vee-dub.