Hi,
Ask for a second opinion and see if those percentages are correct.
There really doesn't seem to be set protocol on this treatment. ie; some have surgery first then treatment. Some have surgery and no treatment; others have treatment and then surgery or no surgery.
Take notes when you go to the dr's and always have someone go with your father. Ask lots of questions about the possible complications of both treatments and weigh it all out. But like others have suggested; go to a 'cancer center' and not just a regular hospital.
Hopefully others who had that type of surgery will let you know what to expect afterwards; and quality of life issues.
As to what to expect for rad and chemo treatment: Here is a link I posted for someone else on the board for their father; regarding my Dad's treatment (he's 69).
http://www.oralcancerfoundation.org/ubb/ultimatebb.php?/ubb/get_topic/f/2/t/000761.html But remember everyone's treatment is a bit different and it all depends on the area of cancer, size etc. And everyone takes to treatment differently. But we also met a 71 year old man that did pretty good as well. Treatment does get rough from about week 3 onward. One dr told me that older men are tougher then the younger ones ha.
Your father has to do what 'he' is comfortable doing.
If you have any questions please ask. I know this is a very scary time for you.