Doc,
Just a typo error, it looks like a 1657 to me, not a 1667.
I have most of those duplicators that Marty sold.
That was a popular one back in the day.
The 45-Hydro class loved that propeller.
Now the ABC 2217, 2219, 2317, & 2319 pretty much dominate
Heat racing. I did well over 100-1657’s...