Rebuilding a commercial speaker?

I have a pair of Klipsch KG 5.5s. Not too shabby, but not bleeding edge high end either. These have 2 10inch woofers each along with a Tractrix horn in each fairly large box. I'm currently using them with the horns disconnected to supply bass only to supplement my experiments with full range speakers. They are made with reasonably nice veneer over MDF, but the internal bracing is pretty nonexistant, so they are a bit boomy. I'm considering going ahead and trying to pull them apart and rebuild them with significantly enhanced internal bracing, but I definitely don't want to end up with a pile of broken MDF at the end of the day. I also have no specs on the stock speakers (and apparently Klipsch doesn't either), so I don't know how they compare to more recent offerings. Supposedly these go to 35 Hz stock, but I think thats a bit optimistic - I'm thinking after some bracing, stuffing, and port manipulation I might do better. I probably should just play them as is and save up to have some "serious subs" built, but thought I'd throw this out there for opinions.
 
After thinking about it some, I think I'll just try to add some bracing through the speaker holes and leave it at that. I think I can get some significant improvement without all the hassle, and this won't end up being a "reference/statement" loudspeaker even were I to go to all the trouble of pulling them apart and reassembling.