It's hard to say from the pics but it looks like your driver has been reconed once already. The surround looks more like an accordian surround than a foam one. Looks like that 18 led a hard life ...lol...sorry, I would look on the back side of the cone and see if you can find some numbers to cross to see what has been done already. If it was me, considering the price you paid for the frame I'd pony up for the JBL 2243 recone kit. That would be on kick ass sub.
Kelly