The Origin of the Yiddish Word for a Shabbos Siddur: Rummel

My father, z”l, used to call a siddur that only had Shabbos and Yom Tov tefillos, a rummel. I always wondered about the etymology of this word and its primary meaning.

The word is actually an abbreviation with the letters, resh, vav, mem, lamed. In Yiddish the letters stand for: Rabbinish Un Masorishe Literatur viz. Rabbinic And Masoretic (traditional) Literature.

A recent book about Jewish book dealers in 19th century Europe has catalogs from that period with Hebrew sections entitled: Sifrei RUM”L. In Hebrew the same abbreviation in that context stands for Sifrei Rabbonim U’MeLumadim, books for Rabbis And Scholars. (Be’Ha’nu’to Shel Mokher Sefarim, At the Bookseller’s Shop, by Hagit Cohen, Hebrew University Press, 2006, p. 31, n. 27)

Open issue: How did the word rummel get limited to a Shabbos siddur?