Hm, that speaker is different than mine. Mine has the resistors to sub for the not-there field coil mounted under the big plastic cover on the back of the magnet. Interesting. Also looks like you're missing the rectifiers. Should be a pair of 5Y3's.
The turntable upgrade was common. Not too long after the 800B came out with its 78 rpm changer, the LP format really took off and many people wanted to play LPs on their recently purchased and still very nice Scott radio. One of the original table offerings was a Thorens model, so its possible that CD43 just drops right into the original cutout. Looks like they did a nice job of it either way.
There is a thread on antiqueradios.com about a tone control modification for the 800B that makes a tremendous improvement in sound. The stock controls are sort of strange. The bass control works by bypassing a high pass filter, and I think the treble control is simply variable low pass filter. It doesn't sound that wonderful, poor bass and fairly shrill mids. The modification posted over there removes the stock control circuitry and substitutes what you'll find in the back of the RCA books from the 50s and 60s for a tone control, but it uses two of the existing tubes in the radio. its basically moving a few wires around and adding a couple of caps. I did it to mine, and its just a world of improvement. The amplifier and speaker are quite capable, but the stock tone circuits needed help.