Well I don't really know anything about Lima. I drove through it once or twice. I would say look for the biggest river system in the area or looks for some big lakes. That is where you should find the bigger cats. Either than or make a trip down to the Ohio or Scioto rivers.
I live in lima, i mainly fish rivers. The Ottawa, auglaize and blanchard are all very good for cats this time of year. The auglaize holds some flats north of dupont. This is the best time of the year imo to be cattin'
You might wanna try ferguson res. have always heard good about it. There are also a few conservation clubs between allen and hardin county and they have a good population of healthy cats there as well. You best bet though is to chech the bait shop off res. road on the east side of lima.