You don't give a date for this "Letter from London," but I assume that it is prior to the PBC's document on the salvific nature of the Old Covenant for the Jews.
Recently, we have also seen the Pontifical Biblical Commission (PBC), a delegation overseen by Cardinal Ratzinger, release a relativistic statement based the new modes of thought supposedly necessitated by the Second World War. The Jewish People and Their Sacred Scriptures in the Christian Bible was a work described by Ratzinger as recognizing "the Jewish reading of the Bible as a possible reading."On the other hand, if Michael Davies is still writing such stuff even after the 2001 PBC document, then it would be cause for concern, indeed.Building its case on such a basis, Reflections seems to be less of an aberration than the next step in "interreligious progress" with the Jews. But what was so different about this statement to cause such shock and disdain in those usually defending any and every perceived "development"? Was it due to the fact that it came from one of the same American bishops who had shown an inability to be trusted in the most rudimentary of responsibilities? Or was it just too big of a step taken too fast?
Either way, the revolutionary blitzkrieg of ecumenism has not been stopped, but merely forced to re-examine its tactics and try another approach. Perhaps the Reflections document should have been content to focus on the newly-discovered permanence of the Old Covenant, thus laying the groundwork for a future rejection of Christ's mandate to baptize all nations. Such a document would have been defensible (or at least defended) as it would have reiterated something John Paul II had previously taught. In fact, even though most of the usual suspects eventually voiced displeasure with the document, some expressed what can only be classified as reserved disagreement ("it may not have phrased Church teaching in the clearest terms") or even veiled support ("nothing in this document is necessarily new").
It should be noted that this document is absolutely not part of the Magisterium in any sense whatsoever. Paul VI at least had the good sense to remove the Magisterial authority of the PBC when he gutted it after the Council.
As for Davies' letter, it appears to be published after the PBC document, coming in March 2001.
On the other hand, if Michael Davies is still writing such stuff even after the 2001 PBC document, then it would be cause for concern, indeed.
Davies actually does seem to touch on this subject:
Mr. Guimaraes tells us that there can be exception to this rule and therefore he does not accept the teaching of Father Feeney. He would, presumably, agree with me that Jews who are convinced that the old covenant still prevails and are perfectly sincere and conscientious in their observance of the Jewish law can be saved. (http://www.traditioninaction.org/polemics/davies.htm#fromlondon)
This seems to me to be at about the limits of what can be argued from the Holy Office's 1949 letter to Abp. Cushing (Jews have supernatural faith from the Old Testament, after all).