To fatten a vocal in Reaper select ReaDelay then Vocal Fattener.
It does a fairly good and subtle job of it.
The PG 57 did a nice job but there're some aggressive 1st sounds that could be automated or addressed with a fast compressor setting.
I kept waiting for the strings to play counter melody or some interesting harmony lines. They do a nice job of support/dressing as is but a little embellishment - not unlike the glock, would've been nice with nice samples like you've used.
Lovely stuff.


Cheers
rayc
"What's so funny about peace, love & understanding?" - N.Lowe