The best place to start is
www.pearsoninfo.net. That is THE Pearson website, and also happens to be the product of one Dan Pfeiffer, who used to own a P-26. Dan's site will have the info since he has a whole section devoted to the P-26. Also, check this site for a link to D&R up in Mass. They bought a bunch of Pearson parts and some molds when the original Pearson went out of business.