I should now better than to write letters after midnight.
Another member questioned my Nervar/49D compatability statement.
So I dug out my Nervar chainrings along with a set of TA.
One on top of the other, they seem to have an identical BCD.
My apologies for any confusion I may have caused.
Will try to figure out why I thought they were different tomorrow, if I can locate the arms.
Amir Avitzur
R"G Israel