Congrats on the increase in bench strength--that's a big jump. Now let's crunch some numbers. In your zeal to get stronger, you've packed on a LOT of excess fat. Even if we generously assume you gained 15# of muscle last year, which would be a phenomenal accomplishment for a 48 y.o. (assuming you didn't take steroids), it still means that about 40# of your weight gain was fat.
If you diet hard, you can average about a pound/week over the course of a long cut. This means you are looking at 35-40 weeks running a significant caloric deficit to get this excess off. Unfortunately, a significant caloric deficit such as this all but precludes the gaining of muscle mass (and may lead to some muscle loss).
As for gaining another 10-15# of muscle, that will take a natural lifter at least 3-4 years of dedicated lifting with strict adherence to sound dietary principles--assuming you want to accomplish it 1) without steroids, and 2) without gaining yet another 40# of fat. OTOH, if you keep pounding the food, you could conceivably gain this muscle in a couple of years.
As I see it, you have three options:
1) Rapid (ie, 35-40 weeks) fat loss. Upside: Rapid fat loss. Downside: Will not gain any muscle during this time, and may even lose some.
2) Rapid (1-2 year) muscle gain. Upside: Further big jumps in strength/size. Downside: Gaining another 40# (or more) of flab.
3) Re-comp (ie, exercise/diet plan for slow weight loss + a little muscle/strength gain). Upside: Will eventually get you where you want to be. Downside: Can be frustrating, as both weight loss and strength gains occur at a slower rate than they would under Option 1 or 2.
Which option is best is obviously a matter of personal opinion/goals. Whichever approach you choose, there are a number of posters here who will be happy to help you work out the details.
Edited for a big (and dumb) math error.