If the population is 30 years old then I would add some different genes. First id an excellent source of LMB from your area of the country (not Fla but more northern for example). Make your deal in advance for a set number and quality of adult 1 to 2 lb LMB to be delivered next spring (26). In the meant time harvest the same number of LMB usually harvested plus the number you are going to add (harvest the low RW fish). Next spring (pre spawn) add the new LMB and habituate them for at least 24 hours. Depending on pond size you should not need a lot of new LMB. 10 fish per acre is more than enough.