Hey Keith,
You've got another gem. Nice going!
The R (probably short for 'rudimentary', since it lacked the automatic shut-off function and cord reel) was introduced in late 1960 and was discontinued in mid-1963. The aqua G came shortly afterward in early 1961, so there would have been more Rs sold with the G-colored attachments. The aqua pn cords came out around 1962, so that may indicate that your cleaner is a '62 or '63 unless it was a later upgrade.
I have a Model R, too, with the gray power nozzle cord and attachments and pn cord with the gray accents; except for the PN-1 with the teal-green bumper.
In case you don't know, the serial number is stamped on the side trim of the bag chamber (remove the cover to view).
I like how you tend to buy cleaners with the original attachments; including the Rug Washers. If you want to go the whole nine yards, you'll want to find the contemporaneous triple-brush aqua B-7 polisher & scrubber, which succeeded the original gray and ivory one.
eBay photos of aqua B-7s—note the first one lacks the polish can holder (1961-63):
