the book is "草書禮部韻寳" by emperor 仁宗 of 宋 dynasty. it's for looking up how a chinese character appears in 草書 (cursive script), as you know, ordered according to rime.
well, it's a calligraphy dictionary. you look up a character, see how it's in 草書, nothing more; no explanation, no 反切.
if you're looking for a rime dictionary, you may download all 5 volumes of "鉅宋広韻" (宋版廣韻), from 重要文化財（漢書） of the national archives of japan.
edited, info added about how to lookup a character in rime dictionary.
in general, you already know the 聲 (Tone) & 韻 (final) of a character, then you use the rime dictionary for confirmation, or look up characters in the same 韻目 (rhyme groups). if you don't know how to pronounce a particular character, forget it :(
the wiki page explains it:
the characters were first divided between the four tones
Each tone was divided into rhyme groups
since 平聲 (level tone) has more characters, it's further divided, that there're five group:
上平聲 upper level tone
下平聲 lower level tone
上聲 rising tone
去聲 departing tone
入聲 entering tone
then, each group has several 韻目 (rhyme groups), each group list all relevant characters with the same 韻 (final).
talking about tones & finals, it's easier if you know cantonese, one of the dialects which still has 入聲 (entering tone); that, if you know the pronunciation, or, from the end of finals (-p, -t, -k); you know that it's 入聲字, directly.
now, let's try 鬱; in cantonese: wat1, sound file
first, to determine it's in which 聲 (Tone):
it belongs to 入聲 (entering tone), which is directly by the cantonese pronunciation. or, if i try to write the romanisation, it's "wat", which ends with "t", a second hints of 入聲字.
secondly, pick up the 5th volume of 鉅宋広韻﹒入聲卷, in the first page, read from rightmost column, from top to bottom; until you find a character sounds similar to 鬱
that is, to look for 屋, 沃, 燭, 覺, 質, 術, 櫛, 物 in sequence. then, 物 sounds similar to 鬱. because i know both the cantonese pronunciation, they're similar, if in doubt, the two characters (文弗) above 物 provide 反切
it should read as "物﹒文弗切", which means the pronunciation of 物, one can combine the 聲母 (initials) of 文, with the 韻母 (finals) of 弗:
弗 is also sounds similar to 鬱, which i've strong confidence that character "鬱" is in 韻目 (rhyme groups) "物"
now, turn to the page of 物, voila, 鬱 is here :)
in mandarin, 鬱 is yu ; without hints of tone; imo, it's very difficult for mandarin speaker to use rime dictionary. you may try it by yourself 😼
have fun :)