Hunchback: per TR:3025 and 3039, first built in 2572.
Victor: per TR:3025 and 3039, first built in 2510.
Per TR:3075, the Mackie MSK-7 series "covered new factory models from the late 25th century [i.e., 2475+], mostly built around a powerful autocannon and a number of heavy energy weapons."
So the Mackie is probably the first, beating out the Victor by a few decades.