It was HP, ST and DX equal on the Jig familiar (first at Level of tatoo, then at Level/3) before the
final UC & Jig tweak, now ST on Jig familiar was reduced to Level/5 (HP and DX is still Level/3) while all the UC "weapons" got a "+" boost.
First of all, if somebody would figure out what the relation between ST, UC damage and UC level is, then we could start calculating what level of UC does a Jig familiar have.
And second, somebody would have to find out how Endurance actually works (from a ToE or LToE), only then you could figure out what the level of Endurance a Jig familiar trains.
Anyway, best bet scenario until now is HP=DX=UC=Endurance=(Level of tatoo / 3), while ST=(Level of tatoo / 5).
Just my two cents...