My first "real" trad bow was a Super Grizzly. I bought it new old stock from a place that bought out an archery shop and was selling all kinds of near stuff. That was 1981. Still have the bow
BH should be anywhere from 7.5 to 8.25, but if yours is shooting well at 7, why fight it. If it is quiet, even better. My guess is you have an endless loop string with it?? I like mine up around 8" but no less than 7.75". Enough to get the string just out of touching the end of the grooves in the limbs.
Killed my first trad deer with it. I now own three. All are LH. I did measure my original SG. It is marked 50 @ 28. It has lost a lot of its gusto. It is around 40lbs at 27 for me. I always thought it was me getting stronger.