Remake files for a Snap-Fit PETG Google Review Plate

Already have all the 3 files, just need to edit them as they are not right. Files I have are 3MF files
Currently the base plate and plate are not the right size and how they attach does not work.
So need to:
1. Fix the sizing
2. Fix the connection
3. Have letters to the Plate printed separately, plate to have recess for letters and QR

I’d like a clean, durable Google Review display that comes off the printer in three distinct PETG parts and a separate set of letters that press in afterward. Each of the three main sections must lock together with a reliable snap-fit; no screws or adhesives anywhere in the core assembly.
The coloured letters are to be inserted with a snug fit.

Here’s what I need from you:

• Precise, print-ready 3MF or OBJ files for the three plate sections, plus a separate files for the individual letters. Plan here is to have a whole sheet of same letters.
• Tolerances validated for PETG on a typical 0.4 mm nozzle so the snap joints engage firmly without forcing.
• Simple assembly guide or annotated screenshots that show how the sections align and how the letters insert.

1. Base – 130 mm × 130 mm, with the text “Leave a 5-Star Review” raised or engraved so it prints crisply in PETG. (Example Image attached)

2. Plate – 170 mm × 130 mm, featuring a recessed pocket sized precisely for the QR insert and recessed where letters and stars are to be inserted.
For this one I want to print all the letters and stars separately and then have an insert on the plate to add the letters. (Example image attached)

3. QR Insert – a separate piece that snaps or press-fits into the plate’s recess. I will supply the actual QR graphic; you only need to model the insert to the correct outer dimensions and depth.

Max budget is $120 AUD