T-shirt Graphic Cleanup & Prep for Printing

I have a completed Rebel Ranchwear T-shirt graphic that is already approved. I need an experienced Photoshop/apparel-production freelancer to make one small branding correction, prepare the existing artwork for professional T-shirt printing, and provide a separate version of the existing branding for a small chest print.
This is a production-cleanup job, not a redesign.
I will provide two reference images:
1. MASTER ARTWORK — This is the exact artwork that must be used as the source. The design is approved.
2. SHIRT MOCKUP — This shows the approximate desired size and placement of the large back print. It is for placement reference only. Do not extract or recreate the artwork from the mockup.
LARGE BACK ARTWORK
The small REBEL RANCHWEAR lettering beneath the longhorn skull needs to be cleaned up so it is clearly legible when printed.
Please preserve its wording, location, approximate size, aged-cream color and vintage appearance. A very slight increase in letter weight is acceptable only if necessary for print clarity.
Do not change the longhorn skull or RR mark.
Everything else in the master artwork is LOCKED and must remain visually unchanged, including:
American flag and landscape
Sunset, fence and grass
Colors and textures
PATRIOTISM and SPINE typography
Script lettering
Existing vintage distressing
Overall proportions and composition
Irregular feathered/distressed outer perimeter
The distressing within the main lettering is intentional. Do not clean up, replace or recreate the main typography.
SEPARATE SMALL CHEST LOGO
Please also provide the existing longhorn skull + REBEL RANCHWEAR + RR branding as a separate standalone transparent file for an upper-left chest print.
Target finished print size: approximately 2¾–3 inches wide.
It should retain the same design, colors and vintage character as the branding in the master artwork. Optimize only what is necessary for the small lettering and fine details to reproduce clearly at this size.
Do not redesign or reinterpret the skull, RR or branding.
NO AI REGENERATION OR RECREATION
This requirement is very important.
The supplied master artwork must remain the source artwork.
Do NOT use generative AI, AI image generation, generative fill, AI recreation, or any other process that redraws or regenerates the design.
I do not want a newly generated image that merely looks similar to my original.
Corrections must be made manually and locally to the supplied master artwork. Pixels outside the specific areas being corrected should remain untouched whenever possible.
No global AI enhancement, redesign, restyling or reinterpretation.
FINAL DELIVERABLES
Large back artwork as a high-resolution transparent PNG
Approximately 5000 pixels wide, with height proportional to the original artwork
Original aspect ratio preserved
300 DPI
True transparent background
No black or white rectangular background
Existing irregular feathered perimeter preserved
No stretching or cropping
Separate transparent PNG of the chest branding, optimized for approximately 2¾–3 inches wide
Both files ready for professional T-shirt printing
The goal is simple: preserve my approved artwork, improve only the small REBEL RANCHWEAR lettering, prepare the large back graphic for production, and provide a clean separate version of the existing skull/REBEL RANCHWEAR/RR branding for the chest.
Please only apply if you are experienced with manual Photoshop production cleanup and apparel print preparation and can complete this without AI regeneration.