The Lettermen tracks were first issued as singles in 1960, when they had a short record deal with Warner Bros, right before they signed to Capitol for the rest of the 60s and 70s. These Letterman sides can be found over on 45cat.
I think Timepieces was a series, similar to "Capitol Starline" or "Elektra Spun Gold" over on the vinyl side. I saw others in the series back then but this was the only one I bought.