Note
QST, Jun 1977, p. 160.
QST, Jan 1980, p. 180. (2m model 4-40P)
QST, Mar 1981, p. 168.
Lunar took over the SCS product line when SCS closed sometime early in 1977.
This is the first reference I found for either Lunar or SCS, so these amps had probably been around for a while.