Good News Bible inserts a paragraph break here, which is appropriate.

When they had accomplished these things: Good News Bible says “When it was over,” which is a bit weak. Better models for this clause are “When they had completely conquered the enemy” and “Their victory over the enemy was a great accomplishment, and when it was over.”

With hymns and thanksgivings, they blessed the Lord who shows great kindness to Israel and gives them the victory: For blessed see the comments on 1Macc 4.30. This last part of this verse can be interpreted in two different ways. It can mean that the Jewish soldiers thanked the Lord for that particular victory (so Good News Bible, New Jerusalem Bible, Goldstein), or that they thanked him for always showing Israel great kindness and giving them victory (so Revised Standard Version, New English Bible). New English Bible has “the Jews praised with hymns and thanksgiving the Lord who showers blessings on Israel and gives them the victory.” We prefer the latter meaning, but translators may choose either with confidence.

An alternative model for this verse is:

• The victory was a great accomplishment, and when it was over, they sang grateful songs to praise the Lord, who shows such great kindness to [his people] Israel and gives them victory.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.