Hi. No worries. Happy to help. Yes whatever original file of the Ossum jeep in Step 1, scale them up to 133% or 1.33.
As for files in the step 2 created by me, do not need to scale up. Just print as it is.
Please share some photos in the "Made" tab when it's printed and report if there's any issue.
Cheers! Have fun. You're gonna love it!