Your father is running old age.
And having multiple skin malignancies and also senile warts
also called seborrheic keratoses.
Nails are atrophied.
All the changes and diseases are related with old age.
I think, first of all, he must be psychologically boosted up.
You should try to improve his general condition by diet and light exercise.
All nalignancies and senile warts should be removed by excision and cautery, one by one.
Before that , series of investigations should be done to rule out any other disease.
I hope, he may be benefitted a lot.
But, you should consult dermatologist
for perfect treatment.
Dr. Ilyas Patel MD