Honda-SOHC

I am having a bit of a spring clean out and found a caliper that looks like a CB550 but is 10mm smaller in width. The arm/bracket are identical to a CB550 and fits the arm/bracket a treat . Is also marked with TOKICO Y on the front. Anyone have a clue to which Honda this is from? Sorry, but sill can not work out on how to post a photo.

Maybe, one of the 1st day of production CB550KO up for sale;
http://www.ebay.com/itm/1973-HONDA-CB550-KO-LOW-VIN-255-1ST-DAY-OF-PRODUCTION-RARE-RARE-RARE-/350928579473?pt=Motorcycles_Parts_Accessories&hash=item51b4f92b91&vxp=mtr

Where is VIN number 1???

Anyone fancy a gamble on some nos parts?
http://www.ebay.co.uk/itm/Honda-Suzuki-Kawasaki-Yamaha-NOS-parts-1960s-90s-ideal-for-auto-jumble-or-Ebay-/261435737420?pt=UK_Motorcycle_Parts_13&hash=item3cdec8c54c

P&P is a bit over the top. The seller also has a full exhaust system for a CB500/ CB550.
http://www.ebay.co.uk/itm/Honda-CB500-four-K3-CB550K3-Mufflers-exhausts-system-new-and-unused-/251494200890?pt=UK_Motorcycle_Parts_13&hash=item3a8e38f63a

As the title says: As anyone bought parts from Parts N More located in Canada? They seem to have some nice parts bit not OEM.
Love to hear from anyone that has ordered from them before. 

These are Identical to Honda part number 51611-300-000. I have a friend that insists that the can tell a replacement part from OEM honda part but, this time he couldn't. And i got confused on which was which in the end.

  http://www.ebay.co.uk/itm/281248014499?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
The price is great also.

Some time ago i asked on whether a CB550F tank was any different to a CB550K3. I had many replies and the one that stood out was they were different sizes.With the K3 being about a inch longer than the F. One quote i remember was one member telling me that if i put a K3 tank on a F that the seat wouldn't close. So i went out and found someone that has a CB550F2 and a CB550K3 to put this to the test.
I sent him the measurements of my tank just to see if there was any difference. The first result was the two tanks that he has are identical. OK, the K3 he has is unmolested, so the tank on his F2 is wrong maybe. He then went on to use the measurements from my tank and found that they were all the same.     

The big question is: Are the flasher relays for LED the same as a normal 2 pin indicator relay. There does seem to be a big price difference, with the LED being a lot cheaper. Can any electric guru's please advise.