I'd be concerned if it's been like this for 2 decades that you've got some really old LMB that are pretty small. I'd take out every LMB I could before I put in new forage & as Brett said take out all the HBG you can. (anyone say rotenone?) I don't think you could possibly come close to taking out enough LMB, no matter how hard you tried. The crappie are another story all together. Since you're bass crowded they probably aren't surviving to adults, but when you cull the bass down and add forage you might be in for a crappie surprise.
I'd want the forage, when stocked, to go into the new younger bass, and your first spawn. I really wouldn't want to start fattening up a 6 year old 13 inch bass.
If you want large bass, I'd lean higher on the BG numbers. And as above lots of types of forage. Tilapia would be good to lessen the pressure on your BG the first year. Might not hurt to feed the BG's as well if you can.
The new Florida genes will help, but remember you probably don't have bad genes in these fish, they're just not growing because they don't have food. So when they do spawn and recruit those fish should be fine if you've got the forage.
