When you spray the poly, just be sure mask off the neck pocket and heel where they will mate when the neck is inserted. You want the glue adhering to bare timber on both faces.
Thank Mccreed , Definitely going to tape then up as well as the fret board etc.
while on the topic, I got two shims I’d need to fit in the pocket, my thoughts are to glue them in & clamp down one by one leaving 24 hours between each shim to set.