This is the nameplate that Lunn Laminates affixed to Louis Claassan's Spirit of Fellowship. Note that G. D. O'Day Associates, Inc does not appear on the nameplate. US Yachts was the sales and marketing agent for the Dolphin. Lunn was instructed to start its hull numbering series with the number 200.

An interesting anecdote here. Lunn modelmakers apparently made 1/10 scale models of the Dolphin that owners bought or received with their boat. Roy Berg, the former chief engineer of Lunn, and 1st owner of Black Dolphin, Lunn Hull # 219, assembled one of these models. Son Doug took a picture of this model recently and sent in the following photo of the nameplate that is on that model. Note that the hull # is 201. I'll bet there is a story here...
This is the nameplate that Jay Picotte's Recovery has - it does not help us with hull numbers but ...

The following plate is the nameplate that Eric Varty found on his Canopache, Yankee hull # 188. Yankee placed their nameplates on the main bulkhead arch facing aft.

This is the nameplate from Richard Mc Connell's Fire Escape, Pacific Dolphin # 299. Note the Dolphin arcing between the words Pacific and Dolphin
As yet, we do not have a sample J.J. Taylor & Sons nameplates - or even know if they had them. In 1972 boat builders were required to mold or permanently affix identifying information on the transoms, known as HIN #s (See following article) According to Paul Ingle, his Pacific Dolphin Seminole has the following HIN # number stamped on his transom PDM2840577. Using the information provided by Steve Henkel in the article below this would mean PDM = Pacific Dolphin Marine; 284 = Hull number, 0577 = May, 1977. In the Dolphin 24 game, and failing to find a classic nameplate like those above, this Hull # is the kind of number we want to find.
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Here's some useful information from Steve Henkel's book, Boating for Less: How to Save Money When Buying, Owning and Selling Your Power or Sail Boat. This book is a great resource for sailors. International Marine is the publisher. The second edition came out in 1992.
" The hull identification number (HIN), stamped on a tag or molded into the transom of boats built after November 1972, is generally a series of 12 letters and numbers as set up by the U.S. Coast Guard. Henkel's example: ZTYSR384A787. He says that some manufacturers did not follow the prescribed code exactly. For those that did, here's how it works:
ZTY -- This is a code for the manufacturer. CHL means Cheoy Lee. SSU means S2 Yachts. ZTY means Ontario Yachts. SR384 --The next five characters denote the model identification and production number of the specific boat in the series. SR384 stands for Sonar 384. A7 -- These two characters indicate month and year of the Coast Guard certification of the model. The letters A-L designate the months January through December. The numbers indicate the last digit of the year of certification. (This could be a bit confusing for those whose boats which may have been built either in the 1970s or 1980s, for example. It appears that no one expected them to hold up so well for so long. Fortunately the next set of numbers will probably clarify it for you.) The boat in the example would have been certified in January 1987. 87 -- These last two characters indicate the last two digits of the model year, which Henkel says normally runs from August 1 through July 31. In the example, the model year runs from January through December.
Henkel says this information may come in handy when you¹re buying a boat that seems older than the seller says it is. If you don¹t have a clue about your boat, it may also come in handy, since it will give you a few important hints. He also notes that the engine serial number on an inboard engine is usually stamped on the block and may also appear on a tag on top of the transmission or elsewhere. The serial number on outboards is usually stamped on a plate riveted to the stern bracket."
Patience...