This bike was "outed" on the iBOB list, and quite a few people asked me about it... My response was posted on the iBOB list by a fellow listmember (search the archives, which are on the same page as the CR archives)...
I suspect the repairs were done with original Singer parts, but of course, these weren't worked the way the Singer shop would have done it. That may be why the lugs are similar, but not the same. Also the fork bend is appropriate for a 1979 Singer, but not a 1960s one.
Finally, I always felt the "sports tourer" or "racing" Singers, while they are lovely bikes (I own one myself), are much less desirable than a true randonneur bike with all the right details. But the latter rarely, if ever, came to this country in the old days. A few have made it over here recently, both new and used.
Jan Heine, Seattle