Volana question

I have 2 minarelli P4 engines.
There are some numbers stamped on the flywheel/volana.
One has the numbers 31.02.74 on it and the other has 31.02.76
Is this the date it was made?

Ok, have managed to solve this one myself.
I have a 3rd round case P4 engine with the numbers 31.02.30 on the flywheel
So it is definitely not the year of manufacture, unless minarelli were making this engine in 1930, & I don't think they were!