Internal project numbers, as we know them weren't longer, than three digits, I think. And the number "0310..." was used for
vrious other Focke-Wlf projects, too, so I'll agree with lark that the give number is no direct indication for the Fw P-number,
which is still unknown then.
I know, that those numbers, which are quite probably just drawing numbers, were given as project numbers in several
publications, for example in Novarras volumes "Die deutsche Luftrüstung", but it should be confirmed before taken as a
hard fact nevertheless.