Your situation sounds very similar to me... I was away from the game for 10-15 years, and was probably around 4.0-5.0 at the time (although not sure). This was in high school.
So got back into playing a year ago and came here and saw a ton of posts about “the modern game.” After reading many comments, I basically concluded that I was pretty much hitting modern (or close to it) my entire life.
If you are hitting semi-western to western grip forehands, are you sure you’re also not already hitting modern forehands? If you’re not, I can’t imagine that you’re that far off.
To address some of your other points, do you feel you really need to go ‘modern’ at all? If you are looking to play for recreation and pick up where you left off, maybe you stick to your original strokes. I know some old dudes that absolutely kill it w/ their old-school classic game.
Racquet wise, I used to use a prostaff classic 4.2 si (the stiff version of the prostaff classic). Recently transitioned to a donnay pro one 97 which I absolutely love. Its light but swings heavy and has a great, ‘dense’ feel. Is also a few points headlight. Highly recommend it.