Nice restoration! Those plastic chain guards are rare. What is your serial number? I have always wondered about the white tanks, did they come before the red tanks? There is some literature on the Sensation Antique Mower Facebook page.
Thanks! The chain guard was cracked, but I was able to glue it mostly into the original shape. The torque converter cover was only stained and cleaned up pretty well. My research was also a bit challenged, but what I found would say this is the first Go-Devil (with suspension) after the Sensation Mike-Bike...I think around 1968/69. It still had the Mike-Bike gas tank metallic decal, and as you note was the white color before they went to the red engine and gas tank. Sensation also dropped the Mike-Bike from the Go-Devil at some point and started designating it the Model 104, but has have also seen one with both Model 104 and Mike-Bike decals?

I wasn't able to reuse the original metallic make decal, nor could I find someone to reproduce it. You can also see the change in the gas tank decal design from the later models, which I was able to get reproduced.
