Most Dynaco lovers know that the Mark II power amp was Dynaco's first product introduced in 1955. The first run of Mark II's had a gray tube cage which was quickly changed to the "Dynaco brown" color when they found out that the gray paint on the tube cage turned brown just above the output tubes from the heat generated by the output tubes. The brown cage remained on Dynaco tube amps until the late '60's and the tube cages had a "Dynakit" label. Sometime around 1968 - 1969 Dynaco changed the color again to an almost black color. Some say this change was to modernize the amps and some say it was to match the new line of Dynaco solid state amps just coming out and still others say it was because the new black color better matched the "burned" paint above the output tubes better than the brown color. The new black cages now had a "Dynaco" label instead of "Dynakit" as was on the brown cages. I have had people tell me that they have a black cage with a "Dynakit" label and brown cages with a "Dynaco" label - but - the reality of the situation is that many tube cages have been repainted and some have been relabelled so many times you don't know whether what you have is the original color or label. If you need a new label on your cage get in touch with Kevin at Dynakitparts. Kevin sells replacement labels for the ST-35, Mark III, Mark IV and ST-70 at the link below.
Replacement Dynakit labels