scharkalvin:
Please note that the adafruit usbtiny isp doesn't work with devices over 64K.
Thanks for your reply scharkalvin.
I'm with you. While I'm using a USBasp programmer it's probably the same issue, but I cannot find specific specs that say the USBasp cannot do it. I'm found a page showing an "ACEduino Mega 2560" and a USBasp being used but the information suggests perhaps he only performed a backup- not a restore. For those interested:
https://americanhobbyistblog.wordpress.com/mcu-development/aceduino-mega/