Actually, applying Pecard's is causing more damage to your leather items than good. That's why the Smithsonian museum stopped using (despite Pecard's claims) and this topic has been discussed in depth on various forums since the initial controversy years ago. Pecard's has a rather successful marketing campaign and it seems few people are actually researching the product.
From a moderator on USMF forum;
"Since this controversy broke in Military Trader a few issues ago, I have talked to a number of friends and acquaintances who are currently employed in the museum field as curators, conservators, and registrars. I asked them all one question: "would you recommend using Pecards or any other similar leather treatment on artifacts?" Their first response was always laughter, followed by horror stories about items in the museum collection that are a mess and require constant attention due to what one curator called "Pecard bloom", a white waxy substance that rises to the surface of the leather like oil still leaking from the USS Arizona. Items so treated in the past can never be put in displays where they will come in contact with other artifacts (especially cloth) because they will stain the other items. They are also a constant source of irritation as over time they stain, discolor, and contaminate whatever display material or storage system they are in contact with."
Full thread which is worth reading;
http://www.usmilitariaforum.com/forums/index.php?/topic/24966-preserving-leather/
You can also search the other forums for many more in depth discussions of Pecard's. If you want to continue using Pecard's on your collection that's fine but other members should do their own research before degrading their leather with this superficial product.
Regards,
-Steve