The ending みごと in momotarou

[letslearn]

Hi Guys,
I'm reading a version of 桃太郎.
On the last page it uses the word みごと. I think it is being used as an adverb. Am I correct?
こうして ももたろうは、ぶじに おじいさんとおばあさんのところにかえっていっ た 。 ももたろうにとってなによりうれしかったのは 、 おにたいじというでっかいゆめをみごとやりとげたことだったそな。 めでたしめでたし 。

Thus in this way momotarou returned home safely to his grandparents. It is said that what pleased momotarou the most was that he commendably accomplished his greatest dream of chasing away the Oni's.
They lived happily ever after.

 

[Toritoribe]

Isn't it だったそうな?

Yes, that's right. みごと is used as an adverb there, and it's interchangeable with みごとに.

 

[letslearn]

Isn't it だったそうな?

Yes, that's right. みごと is used as an adverb there, and it's interchangeable with みごとに.

Yes that's right. it is だったそうな?
Thanks for reply.
While I'm asking questions in regards to this book. When the dog first asks to have some kibidango in exchange for accompanying him to oni island, the dog asks... 桃太郎さん。おこしにつけたきびだんごをひとつください。.... why does the author use the honorific お in front of こし?

 

[Toritoribe]

To show the dog's respect towards Momotarō.

 

[letslearn]

To show the dog's respect towards Momotarō.

Thanks