久方ブリダナ…百年前我ヲ封ジタ
タカマガハラノ 野良大神ヨ
我ヲ仕損ジテ石クレニ成リ果テルモ
マダ我ニ拘ッテイルトハ
"石ノ中ニモ百年"カ
…黴臭クモナロウモノダ! (source: 『大神』)
Said by the villain to the protagonist, who's been sleeping as a stone statue for the last hundred years. What I'd like to know is how to analyze くもなろうものだ and what exactly it means. I assume it's supposed to say something to the effect of "It's no wonder you grow moldy." but I'm really at a loss here as to how it functions grammatically.
I've tried googling the phrase in question and came up with other examples:
そりゃあいい加減に暴れ出しくもなろうものだ
来年、再びナツツバキの白さを目にすることはないのかもしれない。そう思えば感傷的にもなろうものだ。
Is it an alternative to 黴臭くもなるだろうものだ? だろう as an indirect statement and ものだ to state general facts? Does that even make sense?