Both are multipatten (omni, cardioid, & figure 8) with tiny switches for pattern selection, roll off, and a -10 dB pad.

The Nady is similar in construction to the Marshall V67G except with a shorter, heavier body, and a U87 type grille. The SP C3 is built exactly the same as the C1. Each had 5 transistors.

Except for one or two observations, I will avoid making comments and drawing conclusions.

This is the front side of the two mic capsules. The capsule on the left had a thicker gold sputtering. The capsule on the right had an almost transparent sputtering.

This is the rear of the two mic capsules. The capsule on the right had a thick gold sputtering on the back. The capsule on the left had an almost transparent sputtering on the back.

In person, I could see no difference in manufacturing between the two capsules other than that sputtering difference (and the red wire comes in from the left on the back side of one of the mics.

This is the back side of the two mics. The Nady SCM1000 is on the left and the Studio Projects C3 is on the right.

This is the front of the two mics. The Nady SCM1000 is on the left and the Studio Projects C3 is on the right.

The Nady SCM1000 has a street price of around $150. The Studio Projects C3 has a street price of around $400 and a suggested retail of $599.99.