i just measured both 19cm and PS and they come in at 10" at the thigh. I think the taper or cut on PS makes the thigh tighter.
side note: not only did luisaviaroma get my order here in 2 days, the packaging is stunning and very elegant.
But your 19cm's are made in Italy, right? They are slimmer in the thigh than made in Japan 19cm's.