that's a sound reinforcement type , may not be a way to get in there it may be glued together , which means a cut off wheel on a die grinder , or a sawzall .
Those speakers appear to be a direct descendant of the century , they may even sound better because of the Ti tweeter especially .
If you bust those speakers out of the plastic you can put them in a more attractive enclosure and have a similar sounding speaker as the century I guess ..really don't know !
The 12" is a later "SFG" speaker it will sound different than a 123A could be better though ...
The mid is probably an LE5-something , mine have le5-2's they just kept "updating" them I'm not sure what number they were up to when your control 10 was made.
The tweeter is all new not even like my old LE20-T , should be better !