I recently acquired a barn fresh 1970 CB750 Diecast (frame # 1037309, engine # 1037588) that I'd like to pass along. It's missing a seat, original pipes, original recessed key switch and a few other small parts but the bulk of original stuff is still there. Frame is a bit crusty in the swingarm/lower footpeg area from sitting in a barn but appears to just be surface rust.

Comes with a clear title and and happy to send more photos and info along. I've applied power to it and all the lights and electrics function as they should, bike has spark so it would not take much to get it running. Engine turns over smoothly with compression. I'd like $3,900 for it as is, but if there's more interest in the parts that can help complete other projects I'd consider parting it out.

Sandcast 1185 / E1232 is listed on eBay.  Looks to be a very clean bike. It's also listed in the registry.

https://www.ebay.com/itm/395415848812

Hi Paul, are you able to post pictures of your bike?
The past discussion on this post makes reference to Honda UK literature which used the term K0 to describe the transition bikes, and your VIN and EVIN falls within this range.
There are several other markets outside of the US which did not start importing the K1 until VINs several thousands later than the US. 
I believe the Japanese market had the transition K0's into the 1051xxx range that I have seen and have pics of.  This particular model had K1 style forks where most of the earlier ones I have seen, still retained the K0 forks.  It would be good to have a detailed spec of what came on your bikes with pictures for reference. 
I hope this helps. 

 

It’s been a while! A few projects got in the way and I’m still busy endurance racing an ex Grand Am LEXUS IS300 a Team of friends. Last week I received an invitation to the Cobble Beach Concours. A few years ago, I won best in show with my 1970 cb750. Took my Benelli SEI there most recently and this September I want to take the Sandcast. I typically don’t attend shows, but this is a spectacular event. Back on it, with a deadline!

The Honda Parts manual tells us that the first K1 frame was 44650 and the first K1 engine was 44806. That tells me that your bike is likely a very very early K1. Keep in mind that there are examples of transition bikes that had a bit of a mix of parts between the K0 and the K1. Can you post pics of your bike?