Apparently nobody in Lowell's front office with an interest in the company history has checked eBay in the last five years?! Or done any kind of general Googling in which that guy's eBay sale would pop up?
Cool.
(I don't know if you know of Chapman Mfg or if you've ever seen the Chapman thread, but several years ago I found a Chapman midget set inside a snap-shut eyeglass case with a 1942 OPA label inside. I ended up sending it to Tracy (nee Chapman) Kammisar, granddaughter of the founder and the current Pres./CEO for the little history display case they have in their lobby. They had never even seen let alone have one that old before. I didn't ask for quid pro quo, but in return, Tracy promised to send me an Anniversary Set they were planning with new tools packed inside a replica snap-shut eyeglass case, but they couldn't find a supplier for the cases! Good fortune did smile down on me, though, as I found another identical set a few years later.

You can find the whole story in the GJ Chapman thread
here.)
The only reason I mention it is maybe your generous instinct to share the PDF with Lowell for them to make a little ordeal out of its public release on their website will somehow pry other older Lowell catalogs out of the good karma universe.
And, because I have a suggestion.
While you're in contact with Lowell, and they are in such a grateful mood for you thinking about them, maybe you can ask them to scan
any catalogs or historical publications they do have and upload it on their website. Neither their 'About' page or their 'Blog' features
any.
Long before your time here on GJ some of us other Lowell fanciers had been scrambling on
the Lowell thread to build some technical history and the only references we had to work with on IA/ITCL are miscellaneous ads from 1919, 1920, 1928, and 1937.
Worth a shot.
I'm with you, of course. IA/ITCL is always my first thought for any old catalogs. But once it's scanned and in the public domain - which is the important part - it can be downloaded and uploaded to ITCL.