That's sad and unfortunate. Experts and dealers of such equipment are a dissapearing breed. I have 2 slide rules; a super cheap plastic unit from high school days, and a full-sized Dietzgen I bought for a dollar (leather case and all). It was in a junked car at a pick'nPull yard. My skills have gotten very rusty, so now I prefer my HP-15c handheld or my HP-42c emulators on my iPhone.