Now that the quality of reproduction taillights lenses have improved (no more peeling paint) I'm unsure how to tell a fake from an original. I have some with 11 flutes and 12 flutes.
Hi Barbara, back when the MARC Meet was held in San Diego, I had the fortune of judging several classes out there, -and one was Area 18 with the late Tim Johnstone as Team Captain. Tim was very knowledgeable on lamps in general ...and the way we were determining is he put a small flashlight up to the red glass portion at an angle and he wanted to see a definitive 'swirl' in the glass. All I remember him saying was that the glass had Lead in it that caused this. Likely we incorrectly scored a few cars as having service replacement or reproduction glass due to the swirl not being pronounced enough for his liking. To answer your question, likely the sure-fire way is to look for any type of distorted or swirled look inside of the glass.
This is one question where I think you have to be very careful defining "original" and "repop".
1First, this is the type of item that Ford tended to have multiple suppliers and there easily could be significant differences between two lenses yet both "original".
2Second, is there documentation that the lenses were originally painted or were they cast using dyed glass? If dyed there could easily be variations in color saturation from run to run, or even within a single run.
3Third, there were almost certainly period aftermarket lenses sold. Would they qualify as "original" (not) or "repop" (no... too old) or what?
Hopefully someone along the line has compared numerous documented original lights to see what, if any, differences in the lenses there are. Also if the original engineering drawings available they should specify the construction (and hopefully variations... if any). If not, could someone sic Steve Plucker on this!
1Karl, I think the one thing that probably played into this is that Ford engineers often gave specific instructions to Vendors as to the procedures and materials to be used. I have seen on many prints where the print made reference to a M-Spec which outlined what materials or components must be used as Ford did not want inferior materials to be substituted by a Vendor that might cause premature failures.
2 I spoke of this briefly above, but as I understood it from Tim Johnstone (-who I think is the one that wrote the revisions for the Standards), the glass was specified as to the composition and it was to have lead in it. My guess is the variation did not deviate much, if any.
3 Aftermarket during that time period would fall into the category of Service Replacement. For the purpose of Fine Point judging and what is acceptable, if there was an aftermarket glass manufactured either back then, -or a reproduction piece today that meets the criteria of the 11 or 12 flutes and had the swirling marks visible, then it likely would not receive any point deduction during adjudication.
To answer your follow-up thoughts, yes the Engineer's prints of A-13450-* will spell out all of the dimensions and design criteria. This applied to both in-house manufacturing and outsourced items. In the top corner of the print will be a list of variation dates along with a EI# (Engineer's Information) that gave a brief description on what design change was made. Depending on the build-date of the vehicle being restored, the print last made prior to the assembly date is what information should be used. As far as questions regarding specifics, I would be happy to do some light researching on this '
if' the Benson Research Center ever re-opens to the public.
