[codefox1]

Well, you'll need an electromagnetic speaker that will fit in the cabinet after you make a new mounting board, you should be able to estimate original size by front of cabinet. Electrically, the field coil is listed at 1700 ohms, and the output transformer (I assume it is also missing) would match the tube (about 10,000 ohms impedence) to the replacement speaker voice coil impedence (most likely less than 8 ohms.) Of course you can substitue a small choke (or resistor combined with slight (15% or so) increase of filter capacitor values since you will be replacing them anyway before firing the set up) for the field coil and use a more modern permanent magnet speaker if you can't scrounge up something more original. Impedence matching is not all that critical, about the worst you could do is have diminished volume.

Yes, you can make an antenna loop (just scrounge a scrap length of electrical outlet wire, (OK to leave insulation on and/or solder scraps for needed lengtkh, and follow the dust stains in the cabinet to learn how many turns it had, and (not certain if a turn or two is missing or over counts,) make you a new one.

As you will find out, this is not an exact science unless you are working on a museum piece or national treasure. Best!
Schematic here: http://www.nostalgiaair.org/Resources/413/M0013413.htm