I agree with the guys, and for a first attempt, it's darned good. You might find that brushing the matt clear will leave streaks and/or brush marks. But, if you're unable to spray, add a touch of thinners to the matt clear, and use a wide, soft brush, probably a #4, and apply in quick, even stokes, going one way only.
Let this dry thoroughly for about 24 hours. If there are uneven areas or streaks, then try wiping over with a soft, clean, damp cloth. If they don't disappear, then another coat might solve things, but the decision is yours of course.
Matt clear can be applied successfully with a brush, but it MUST be thoroughly stirred before, and during use, and practice eventually brings good results.