I recently purchased a kit from a second hand store that was labeled as a '66 Pearl Arbiter kit in blue diamond pearl. From what I have read, Pearl used a reinforcing ring inside the shells...much like Ludwig and others in the day. None of these drums have that ring inside. Most of the hoops are the stick saver hoops though. The wrap appears original, as does most of the hardware. Some of the hardware has been swapped out though. It now sports a vintage Ludwig rail mount for the rack tom. The bass drum leg mounts, floor tom leg mounts, and two oddball mounts on the top of the bass drum all say Pearl across the top, and all drums have the silver Pearl logo. There is no evidense any other badge was ever on these.
I have read somewhere that Pearl was in with many other companies in the day and they all pretty much made entry level stuff compared to the American drum makers. It sounds amazing for being an entry level kit though. Both toms and snare have muffles.
In all reality, I doubt I will ever really know the history behind these...and I am ok with that. They look amazing, play great, have killer tone, and I love em. They will get years of good use from me.