Allen's work is a rather extreme example of the "country community" school of seventeenth-century English history whose intemperate excesses in removing all national issues from the history of that period have been exposed by Professor Clive Holmes. What conclusion can be drawn, for example, from Allen's discovery that Puritan clergy who had cometo the colonies from East Anglia were one-third to one-half as likely to return to England by 1660 as were Puritan ministers from western and northern England? We are not told in what way, if at all, this discovery illuminates historical understanding.
黑体的句子中 if at all，我的理解是一个条件状语的省略，我想还原这个完整的状语从句，以便更好的理解文章的意思。
根据状语从句省略的原则 - 主句从句中主谓相同，方可省略从句主语
if at all 在told 后面的宾语从句中，是从句的里面状语。所以句子被还原为
We are not told in what way, if (this discovery illuminated historical understanding in this way) at all, this discovery illuminates historical understanding.
还原完了之后，我理解起来还是很别扭，所以想请大神们看一下，这里的if at all到底怎么正确的还原，才能顺畅的理解行文的意思。