all parts made by nervex (etablissments aime dubois) were pre-ordered
by makers, importers, and/or distributors in whatever angles and dimensions
that were needed. each part was available to order in at least 4 different
angles. the same part was used each time, and the only difference was
how the angle was bored through the part. i used to import all lugs in
72, 73.5, and 75 for the upper parts, and 57, 58.5, 59, and 61 for the
lower parts.