What does するがり and がんこ mean?


I'm reading a book and the following sentence showed up:

> ふたむかし前の漫画に登場 **するがり** 勉少年や下町の **がんこ** 親父がかけていそうな代物なのだ。

I didn't find anything about "するがり" or "〜がり". I didn't study the 〜がる grammar
yet, but I checked it out on the internet and it seems to be used with
adjectives.

The only word I found for がんこ was 頑固 but I'm not sure if it's the correct word
in this sentence.

Also, what does "勉" mean in "勉少年"? I didn't find any suffix like that.

A longer sentence to grasp the context better:

>
> なぜなら波希（なぎ）が愛用しているその眼鏡といえば、太い黒縁の四角いセルフレーム。たとえるなら、ふたむかし前の漫画に登場するがり勉少年や下町のがんこ親父がかけていそうな代物なのだ。

_Thanks in advance for those who answer my question._




### What does するがり mean?

It appears that you've mis-parsed the sentence. It's not:

> ふたむかし前の漫画に登場 **するがり** 勉少年や...

... but rather:

> ふたむかし前の漫画に登場する **がり勉** 少年や...

The term がり[勉]{べん} comes from:

  * The root がり of the adverb がりがり, usually referring to chewing something hard, but also used in a way similar to the English expression "to get one's teeth into something": in other words, "ignoring other things and focusing solely on one activity".
  * The first half 勉【べん】 of the term 勉強【べんきょう】 ("studying").

Put together, がり[勉]{べん} refers to someone who has their nose firmly in their
books, someone studying very hard to the point of neglecting other things.

### What does がんこ mean?

がんこ is also spelled 頑固, and means "stubborn", as you guessed. Additional
senses include "persistent, obstinate, mulish, tenacious", etc. Both kanji are
part of the 常用【じょうよう】 ( _Jōyō_ ) list, so I surmise that the author spelled
this term in hiragana here simply to break up the text, so it wasn't just a
long string of kanji.




### What does するがり mean?

It appears that you've mis-parsed the sentence. It's not:

> ふたむかし前の漫画に登場 **するがり** 勉少年や...

... but rather:

> ふたむかし前の漫画に登場する **がり勉** 少年や...

The term がり[勉]{べん} comes from:

  * The root がり of the adverb がりがり, usually referring to chewing something hard, but also used in a way similar to the English expression "to get one's teeth into something": in other words, "ignoring other things and focusing solely on one activity".
  * The first half 勉【べん】 of the term 勉強【べんきょう】 ("studying").

Put together, がり[勉]{べん} refers to someone who has their nose firmly in their
books, someone studying very hard to the point of neglecting other things.

### What does がんこ mean?

がんこ is also spelled 頑固, and means "stubborn", as you guessed. Additional
senses include "persistent, obstinate, mulish, tenacious", etc. Both kanji are
part of the 常用【じょうよう】 ( _Jōyō_ ) list, so I surmise that the author spelled
this term in hiragana here simply to break up the text, so it wasn't just a
long string of kanji.

