This C6 is already assembled with PVA glue so it's ready for veneering or painting with just a quick hand sand.
The woofers unfortunately do not fit easily into the rebated holes, but this can easily be solved with a bit of work - sanding or filing the holes will make them large enough, or alternatively you can sand the frames of the woofers to make them a tad smaller. Personally I've found that you can just screw them straight in with a cordless screwdriver and let brute force do the work for you.

This is a great buy for $517 + $43 shipping = $560
Under the island, middle of a mountain / There is a big bad boomin' system
Blowin' speakers, woofers and tweeters / Amplifiers, melted wires