550 spyder builder?

I want to start a new post in an attempt to clarify and consolidate the information I have gleaned from notes and an old eBay purchase. I received great information from my first post. It eliminated some of the possible builders so far. First, the pictures I received show a tube chassis more or less a cage construction. My car chassis lower tube frame is 3" in diameter that angles up +/- 15 degrees rearward under the axles tapering down to +/- 1 1/2" and narrowing at the top and bottom to a sharp edge. The upper cross brace is facilitated by a rectangular hollow bar that bolts in between the strut supports and has a welded bracket attached to mount the spare. The body/shells: the front of this car has 25 slotted air holes in the lower frontal area (not bolted on). Little elliptical air scoops are dummies.
The rear section of the body has only three dummy louvre's rather than some cars having none or large louvre panels.
Original Arizona title listed it as a 1955 Porsche (first registered 10/55). Vin# AZ263172. Builder plate under the hood states Vintage 550 Spyder chassis # 116134581. I believe that number was the original vin from the VW engine and transmission originally in the car. Attached are some pictures of the car as it was offered on eBay Jan. 2004. It had a full compliment of decals. I'm hoping the significance of the real slotted louvre's in the lower front and only 3 pseudo dummy louvre's on the upper rear quarters will narrow the car down to one builder. One of the scraps of paper in the piles of papers suggested there were only two made and the builder was possibly in Mexico?Again, thanks in advance for any information.