What is the Mark I at Petersen Museum?

I guess that's it. Thanks for getting to the bottom of this.

 

http://www.jalopyjournal.com/forum/showthread.php?t=413994&page=3

 

That Bosley is a beautiful car!

 

Hi guys,
The Sadler was very cool, was later re-engined with a SBC and raced here and in the UK, where it blew their asses off at the Brighton Speed Trial. Bill Sadler is still around and even climbs in a race car every now and then. A few Sadlers have survived and are still run in vintage events.
Harold Pace

 

I've posted some photos I took of the Bosley Mk I on my web site here...