I’d hate to sound like a certain Pddy O’Deen, but shellac is your friend.  

Brush some on, with the work horizontal.  It will flow into everywhere and both
tie down the the loose stuff and give a sterile quick drying finish.  Repeat as
needed.  IF you want to knock back the shine, acquire some pumice powder (Sharp
edged, fine graded output of volcanos, Paddy)
Place said powder in a coarse muslin bag, made by taking up a square of muslin
with powder piled in the centre and tying with a bit of string.

Shake the bag over the work to shower with powder.  Use the other muslin scrim
to rub the sharp pumice powder over the areas to knock back the shine as much as
you want.  practice on scrap.

Richard
Yorkshireman Galoot, in Northumberland, visiting the deep south of Herefordshire