[Fot] TR3/4 cam help

[Greg And Alison Blake]

I came across a cam with some crazy looking profiles on it today in a box of spares that came with a TR4a dad and I purchased. It has the following stamped on it:
C-2781
C285-2
C290-2x6

Anyone know what this might be?  Profile on the lobes looks interesting but it also looks like the grinder took a lot of metal out of the cam to create this grind. It is a very small diameter shaft now.

Also in the spares was a Kastner F cam. Anyone run one of these that can send me the characteristics?  The nose on the lobes of the F look really broad and rounded. 

Thanks,

Greg