Could be, but I tend to doubt it - 777 has become the stuff of myth and legend. I have only heard of it myself, never used it.
I process my own B&W and scan it myself - no darkroom coupled with no desire to print optically. I can send my scanned files out and have them printed afer doing my electronic darkroom work on my PC. No disrespect meant for those who still do it in the dark - just a personal choice.
Harvey's 777 is supposedly rediscovered and available at the Frugal Photographer:
I don't know what its characteristics are now.
The last 'registered' sellers of Harvey's 777 were:
Name BEST PHOTO INDUSTRIES, INC.
Profit or Non-Profit P - Profit
Company Type KCO - Kentucky Corporation
Status I - Inactive
Standing G - Good
File Date 10/13/1959
Organization Date 10/13/1959
Last Annual Report 7/1/1980
They appear to be defunct. I have no further information.