What does not work? By reading the comments, I gleaned the source URL no longer works. There’s a working URL in the comments.
You commented out the original source and didn’t tell makepkg about your RPM, so nothing was symlinked to the SRCDEST.
You could add the RPM you downloaded as the source, however since there is a working source URL and no additional tools are needed to extract the RPM, do it right:
pkgname=xerox-c525a
pkgver=1.0
pkgrel=1
pkgdesc="CUPS driver for the Fuji Xerox DocuPrint C525 A and Dell 1320C printer"
arch=('i686' 'x86_64')
url="https://onlinesupport.fujixerox.com"
license=('custom')
depends_x86_64=('lib32-libcups')
source=("https://onlinesupport.fujixerox.com//driver_downloads/Fuji_Xerox-DocuPrint_C525_A_AP-1.0-1.i386.rpm")
sha256sums=('2afdaedf8b29e879946e85c874f815f5267ee2935a4f2643b3967134a45698a9')
package() {
cp -r --no-preserve=ownership usr "$pkgdir"
}