I have a 14 yr. old cover. Five yrs. ago it had worn almost through at the back of the boat. I used iron on patches used for jean repair. A ton of colors to match your cover.Still holding after 5 yrs. Total cost $1.25
I have done the same thing but finally the fabric and the stitching got so old it was falling apart. My boat is a 96 and I bought it new. I spent the money and went Aurora Canvas. What a difference. It will be good for the next twenty years.