I’ve mentioned I have a habit of looking up aircraft registration numbers when I see them. I looked up the Schweizer on Whale Wars to see when it was made, and MFR Year is None.
Ar? 
Could it be that this is a ‘salvage’? I’ve seen some helis offered on eBay that had belonged to A&P schools and/or did not have a dataplate. Maybe it was put together from salvaged parts and is in the Restricted or Experimental category?
EDIT: Other missing information is Engine type and model, and Category.
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IIRC, the FAA has reserved a number of fictional registrations for use in movies and such. I have a hard time finding a cite, though. Perhaps the registration you saw is one of those?
I had not heard that. It did have Sea Shepherds as the registered owner, and it had their address. (The FAA site seems to be down at the moment. I know it showed their city and state. I didn’t pay attention to the mailing address last night, but I presume it was there.) If any information would be considered private, one would think the owner’s name and address would be; not the year of manufacture or engine type.
How old is the aircraft? Did the FAA ever have to re-construct registration data from surviving records?
Or, ask your friendly, local FSDO…
How old is the aircraft? It doesn’t say! 
That’s the thing. Ordinarily the date of manufacture would be there, but it isn’t. AFAIK the FAA never lost their data (e.g., to a fire in the records building).
Searching by name, Sea Shepherd has 3 N numbers - one is merely “assigned” (reserved), there is a Hughes 369, engine type: Turbo-shaft (no mfg), no mfg year, as well as the Schweizer.
I am not going to look up every Hughes 369, but the 6-7 I found all had “turbo-shaft” for engine type and “none” for year mfg.
Just an FAA thing with rotorcraft.
Mfd I can see - by the time it is 10 years old, are there any signifigant original pieces left on a chopper?
(for those who do not understand that Q: pointing the prop at the sky and calling it your wing is not a real efficient means of generating lift. Subsequently, heliocopters shake themselves apart, and just about every piece except the upholstery has to be replaced/rebuilt with truely scary frequency. If they aren’t, they have the nasty tendency to fall apart at really unfortunate times and places. When looking for a heliocopter ride, cheapest is not best…)
The aircraft in question is a 269C. Engine type is reciprocating. Under the engine manufacturer it says ‘None’. Ditto engine model. Classification is ‘Unknown’. Category is ‘None’. Airworthiness date is ‘None’. Picking a random heli I found online, I found another 269C (actually a 269C-1). Engine type is reciprocating, engine manufacturer is Lycoming, engine type is HIO-360-G1A, MFR year is 2006, classification is Standard, category is Normal, and A/W date is 03/26/2009.
So it’s not ‘an FAA thing with rotorcraft’ as far as I can tell. This is the first time that I’ve come across an aircraft of any type that is demonstrably flying, but has virtually no information about it.
Weird.