Sue wrote:
Does anyone grow this form of Syringa? I'd like to know if it's likely
to be completely hardy or if I need to place it so it gets some
protection.
I bought a small one at a garden show at the weekend, largely because I
took a fancy to its attractive, finely cut foliage, as well as the
promise of scented flowers. There doesn't seem a lot of info on British
websites but what I've found so far suggests it's one of the parents of
the 'Persian lilac', Syringa x persica. This one definitely has much
prettier foliage though.

Syringa Protolaciniata's synomym is S.afghanica, the lilac you've got.
Look into this plant under s.protolaciniata.