FJ jump smock sizes?

Hi i am looking at buying a FJ jump smock in splitter b camo (49 euro).I understand its ok from 1941 on time wise
Its on offer at Zib Militaria ,being at the cheaper end i believe it is made by Sturm,Is it worth getting,i am not detail obsessed but dont want to spoil the show either.
There is a small size wouid that be ok for someone 5ft5' 34 waist ,also there is a x small and xxsmall,does any one know if those 2 sizes woud still fit as the price is even cheaper(29 euro).
What date were the helmet covers introduced.?