Earlier versions of "Packard-A History of the Motorcar and the Company" did say that, but the version now being sold omits it. Like I said, a lot of people thought that at one time, including some of the most knowledgeable people on Packards. Since the end of the Cold War, however, the ZIS has been more closely examined and additional facts have come to light.
Ken

For a long time it was thought by many people that the ZIS was the result of prewar senior Packard body dies. Now that the Cold War is history and ZIS are more accessible a closer comparison between Packard and ZIS has been done and the conclusion has been reached that the actual measurements of the cars are too different for them to have come from the same dies. Therefore it appears that the ZIS styling results from Russian admiration of Packard styling rather than from actual Packard body dies. There was an article in the PAC Cormorant magazine about this a while back. There are probably more ZIS in the U.S. now than there have been, but most of them are still probably over in Europe. Hope you find one!
Ken

The northeastern states, New York, New Jersey, etc. have the traditionally old money families. The Rust Belt along the Great Lakes had the heavy industry and the heavy industry magnates. California had Hollywood. Texas had oil. Plus there is probably a difference between the dealerships started before 1935 and afterwards, since the junior cars made it possible for the middle class to have Packards.
Ken

One reason why folks may choose to upgrade the trunk is that as I understand the PAC judging rules, the trunk interior is not to be judged, except by the Best of Show Team "when necessary", which I guess means only if that is the only means by which one car can be judged better than the other. Not sure if PI judging is the same. If trunks were normally judged, maybe more people would try to make them authentic.
Ken

PS. Not that my car would win any prizes in that regard or any other. (Too much junk in the trunk!)

Welcome!
Don't know if you know it but the 51 200 Business Coupe is pretty rare. A one year only model. It came with a wooden platform covered with a rubber mat rather than a back seat and the door panels lined with an extra tough vinyl covered fiber board due to its utilitarian nature. Probably a good number of business coupes had the rear platform replaced with a rear seat by later owners. Any way you choose to restore it, rear seat or not, it is a pretty rare car.
Ken

Glad you found some that fit!
Ken

FWIW, my two 53 Clipper Deluxes (the 200 Deluxe two years later with a new name),one of which I still own, had (has) a thin gunmetal gray colored wood fiber type sheet cemented on the trunk floor. It is similar to the kick panels in the front passenger compartment underneath the dashboard but thinner, appearing to have a vinyl gray type of coating on the top. Whether that would also be true of the 51's your guess is as good as mine.
Ken

P.S. My two 53 Clipper Deluxes also had (has) a rubber mat in the front seat area rather than carpeting.

I'm afraid I do not have a 52 but instead a 53 and I am not certain that their radiator hose specifications are the same. Plus, if you looked it up in an old book, what they were may no longer be what they are now. You probably have about 60 years on those engine supports, you know. Assuming you have the old hoses, take those to the auto parts store to help in getting your new hoses. To also help you in getting your hoses I would suggest you get the diameters at both sides of the mountings of both hoses, and get your own measurements from one side of the hoses to the other, have at least a general notion of the bend required by the hoses, and use all of this at the auto supply store to buy your hoses. When I bought my last hoses they did not have one specially made for either upper or lower radiator so I ended up buying two I had to cut to fit. You can get a hose two ways. One, you can buy a flexible hose with a built in flexible portion reinforced with a metal spring. Or two, you can buy a molded hose with the proper curvature that you can cut to fit. Most auto parts store people ought to help you if you tell them what you are trying to do. Hope that helps!
Ken

For what its worth, I had my car regularly insured as a normally drivable vehicle with USAA (my dad's a vet)and I asked about collector car insurance and they put me in touch with American Collectors Insurance, who currently covers my car. Seems USAA did not write collector car insurance at least when I asked about a year ago. No claims so far. American Collectors didn't give me a hard time about the condition of my car when they wrote the insurance but then I didn't value it very high. I inquired of J.C. Taylor and they were not certain they could cover my car because it was not fully restored and had rust. Give me a break!
Ken

As a lawyer who tries to act so as to avoid being called a "sleazebag" who has handled a number of contested estate matters, I would recommend everyone do a Will giving their Packard or Packards to the person or persons of their choice. Currently under my Will my Packard would go to my Father, who would probably sell it like he did his two Packards he earlier owned.
Ken