IMO, definitely a front clip was welded on--look at this photo posted on the facebook page of the builder:
From the position of the welded seam, the original VIN stamp for the 86 should still be present by the smugglers box, which brings up the questions posed by George as to having a car with two different VIN's that were legally assembled. In California, that would require the DMV to assign a new VIN for the car which would probably be based on the emissions for the engine. The assigned VIN would now be the only legal number to title the car, not a Porsche VIN--something many collectors do not like to see.
This car is registered as a 72. If the VIN by the smugglers box is present, it is a car with conflicting identities that, sooner or later, an owner will need to rectify. The seller has disclosed the discrepancy and in some states there may be no problem but somewhere down the line, someone will be stuck with a car that is difficult to sell,IMO.
My take on this is the builder is legit and wanted to build a car that could be registered as a long hood, not only for "authenticity" but for ease of registration in most states. He did not want to tamper with the VIN as that would be illegal and he likely had the paperwork for the early car so he used the clip, and used the same paperwork to register the final product--very easy to do as no DMV inspection would be required.
Many tributes, clones, and backdates are offered up these days and in nearly every case, the builder lists the VIN of the later tub as the source for title because it is the platform on which the recreation is based. In this case, the clip was used to title the rest of the tub. Using the clip and its VIN to change the looks of the car is perfectly legal. Using that VIN to title the car is sketchy at best as it's a case of "don't ask, don't tell" to the DMV. It's possible to dodge the conflicting VIN issue for a while but eventually, the numbers will need to be reconciled. This is a car to consider at a much lower price due to this problem, or to pass on altogether if you want to avoid future headaches.