It weighs a ton, more than my semi-modern Rotel
Actually, if you didn't know this, there would probably be more than one transformer. One for AC power. And one per channel at the output to match the tube to the speaker load. Then Fisher probably used a lot more metal elsewhere.
The Rotel amplifier would probably be heavier than a modern, mass market stereo receiver of similar rated power. Imagine how light that mass market receiver would be compared to the Fisher!
I've heard that at least some of the Fisher equipment needs minor updating to be usable under regular use in today's world. If I recall right, it's something to do with the standard AC voltage today vs 1960s. In any case, having the thing looked over by someone who knows vintage equipment would be a good idea.