It may look like a duck, it may swim like a duck and it may quack like a duck but Beware. The seller is selling a sand cast frame which may be genuine enough.
hhttp://www.ebay.com.au/itm/1969-69-Honda-CB750-K0-Sandcast-H692-1-Early-custom-frame-1136-/291112971873?pt=Motorcycles_Parts_Accessories&hash=item43c7af6e61&_uhb=1
BUT don't be fooled into thinking that the items the seller also has for sale are somehow linked to this frame, COS MOST ARE NOT
I have to give the seller his due, his marketing skills are second to none, but you need to know what is what and what should be on a bike with a VIN 1136. See my other post about the rear wheel.
PS. Forgot to say that many of these parts for sale are found on both die-cast and sand-cast but then many are not unique to an early 1XXX VIN. For example, centre stand, triple tree, gauges (have cast drives but are from the later sand cast and die cast models) brake splitter and hose, speedo and tach cables to name some