I received Jay Allen's "Pictorial, Soft-Focus, and Portrait Lenses from the Past" a few days ago, and wanted to post a few comments.
The book is bound copy of 55 page computer print-out, describing 50 different portrait and soft focus lenses. These run from the well known and easily available (Imagon, Verito, Heliar) to the rare and obscure, like the Pinkham & Smith Series I through VII lenses. The book is a series of quotes and tables from the original manufacturer's brochures and manuals. Unfortunately, Allen fails to cite (or even use quotation marks) these brochures and manuals, so the reader has no idea where one brochure ends, and and another begins. More importantly, it is more or less impossible to check the veracity of the book. I spotted a few errors, and worry about others. However, getting information about many of these lenses is near impossible, so Allen's book--while not of much value for a researcher--might be of great use for somebody trying to sort through eBay, figuring out the difference between a Dallmeyer A or D, or between a Pinkham & Smith Series II or IV...