The 1953 RLDS edition placed a parenthetical explanation in braces after which in order to prevent the reader from misinterpreting the which as referring to God, the head of the preceding prepositional phrase. Of course, this repetition of “our fathers” is really quite unnecessary since the following verb (were) is in the plural and obviously the Israelites were the ones led out of bondage in Egypt and preserved in the wilderness. Such clarifications should be restricted to footnotes since parenthetical additions tend to get inserted into the actual text. (See, for example, the phrase “or out of the waters of baptism” in 1 Nephi 20:1.)
Summary: Maintain the original text in 1 Nephi 19:10, which lacks the intrusive and unnecessary parenthetical “our fathers”.