first of all you would need the motor with the metal drive gear. you would then need the small white worm gear and the shaft/stud to mount the gear on as well as the oscillating link to connect the white gear to the rotator base.
there appeared to be a transitional phase in the Code 3 SDs between what stampeed referred to above as 1st generation and the 2nd generation where they started using the later style quick change clip style bulb holder assemblies with the 1st generation (pan style) frames before a complete switch...
the ball bearing in the shaft endcap that Stampeed referred to above is a single ball bearing that is about an 1/16-1/8 inch in diameter. i have seen a number of lightbars and beacons with the motors that are missing the endcap.
Red/Red Whelen TIR6 Slimlighter for sale. has approx 8ft of power cord w/o the plug. tested and cycles thru the several different flash patterns and all light segments work. comes with suction cup brackets and suction cups as well as an extra set of suction cups. also comes with an extra set...
you could also consider PAR36 H7600 halogen bulbs that are 37.5 watts. they have a slightly different lens and are a little brighter than the standard 4416.
you are correct on the attachment of the skirt. the skirt does attaches to the base with 3 (i believe they are 1/4" size bolts) adj to the contact plate. it looks like it's normal for a height difference for the belt between the drive pulley and the spindle pulley. the speaker for the CJ184...