My folks have a Mac 1900 and 1019 turntable that they dont use and havent for years. (They bought it when I was a kid) The Mac 1900 is IMMACULATE with the walnut cabinet and all. I dont think there is even a scratch on it. Im pretty sure it still works as they havent plugged it in for many years. It sits in a cabinet. Im sure the turntable is in the same condition. What I dont know is what something like this would be worth. I called them to make sure they didnt give it away or put it out at a garage sale. They hadnt, but my Mom said they had some McIntosh speakers they didnt think was worth anything and gave those to my sister. (I dont know what model speakers they were...)
If they have sat unused for years, they aren't worth the going price of refurbished equipment. Capacitors dry out and rubber parts dry out. Both might work for a short period if you fire them up but they will fail in short order.
The only way to bring the 1900 up to full power is with a Variac and an oscilloscope. Do not just plug this amplifier into 120 VAC and flip the switch. If you bring the amplifier up to power on a test bench, you might save yourself lots of money. Just turning it on will be a very bad idea.
Call Audio Classics for value and ideas on condition.