Okay, I decided to get a little help trying to identify the body and contacted Jim Patterson from House of Ghia. He was terribly helpful. Here's our correspondence:

I have a mystery car and was hoping you could help me determine the year of my body. The body was placed on a 1973 chassis before I bought it and the previous owner thinks the body is a 64, but he’s not sure either because the owner before him actually did the work. The entire car has been dipped and stripped, so no paint, no stickers. I can’t find a VIN on the body anywhere. All the gauges, accessories, lights are in boxes. This is what I know so far without looking though the boxes: It has a 1961-1965 style dash with the ashtray next to the glovebox. I haven’t looked on the rear deck yet to find out if it’s pre or post 1963 because the script is missing and I’m not sure how far apart the holes should be anyway. If you could tell me that, it would narrow it down. Besides the deck script, what should I be looking for to determine if it’s a 1961, 62, 63, 64 or 65? I know it won’t matter that much since almost every part is compatible, but I want to paint the car an original color. One last thing, is there a VIN number on the body somewhere that I’m just missing or did they only put the number on the chassis?? I have a few pictures if they’d help, but they aren’t very good.
-Emily

Emily, here are some items to look at to tell which year body you have. Unfortunately, we probably won't find absolute truth, just a preponderence of the evidence. All yearly references are to MODEL year.

Rear deck lid and script--
12 inch KG script thru '62 model year
9 inch KG script from '63 model year
Volkswagen horizontal script on the left side of decklid. Fm '63 up.

Engine--
40 horse with late huge banana shaped heat exchangers. Mid-63 model yr.

Quarter window--
The chrome pin visable on the outside of the glass has two holes for a tightening tool--A hubcap tool? thru '64 1/4
is completely smooth on the face. No holes. from '64 1/4

Door striker plate--
has three holes for mounting screws. Thru 63 model yr.
has two holes for mounting screws. From 64 up.

Interior mirror--
mounting assembly has long, round, chrome rods extending horizontally from base. Thru 64
mounting assembly is large heavy chrome, with spot for interior light in the center. There are no sunvisor rods. 65-67.

Front hood latch--
Uses a "J" shaped secondary hood catch. Entire latch on hood can be dismantled, BUT a built in bracket on the bottom side of the hood keeps this style hood from being neatly "spooned" together in storage. Thru 65 1/8.
Catch and secondary catch are bolted to the bottom of the hood and entire unit can be unbolted from hood, allowing hoods to spoon together. From 65 1/8

Thanks so much for the help. I've got boxes and boxes of stuff to go through and label. I don't know what half of it is, but this will help me identify the car as I'm going along. What will hinder me the most is trying to sort out the parts that go with the 73 body and the parts that go to the 60's body. You didn't mention whether or not they put a VIN on the body. I thought I read somewhere that they put a VIN plate in above the spare tire, but I looked and I coincidentally have a small 1"x3" cut out in the metal where it seems like it ought to be. Was there ever a plate there? Is there a VIN on the body I should be looking for? Once again, thank you so much for your help. You have no idea how helpful you've already been.
-Emily

No such VIN on the body, or at least, as you have found, a reliable VIN number. If you were really lucky and had a name like Emily Karmann Jr. the III, you might be able to translate a stamped number on the body into a Karmann Werks body number. Then--and here's where the Jr. and the III come in--you just might convince the Karmann factory to look up in old dusty records that body number. But, for we mere mortals, the task is nearly impossible. As you sort out the early and late parts, use the 73 parts as trade items. Sell then at a swap meet, or we do trade our new parts for your used parts.
Jim-

So now I have something to go on while I'm sorting through boxes.