Regarding your questions, please kindly noted, due to your COO is indicated the PF-451, according to statistics, PF-451 was selected for Vitaform "263-PMF" rather than "150-PMF". And we got the reply from the factory, please see below image.
Therefore, the item model no. 91616 is used in #150-PMF and 91716 is used in #263-PMF.