You simply can’t gain muscle while eating at or near a caloric deficit. You might be able to not lose muscle but you can’t actually gain much.

So now I am going to have a walk a more delicate dietary line between eating a little surplus, thus gaining weight so I can put on muscle, then losing a little weight when I’m not attempting to build more muscle.

I’ve done it all before, but it’s been a long time so it’ll take a while to get back into the rhythm. For me it usually helps to go about 8-10 pounds over my normal weight, work out like a beast for a few months, then cut back eating to get back to regular. We’ll see how that has changed since I’m now 20 years older than the last time I was really fit.