This would be a great idea — a retro “make your tw5 look like classic” theme. Especially now that we’re celebrating 20 years.
I don’t have the skills to do it quickly, fluently, or thoroughly. But it soundly entirely doable.
Of course, there are good motivations behind the re-design that informed the newer TW5 interface. Are your reasons for wanting the “classic” look mostly about familiarity and aesthetics? Or are there any differences where you could benefit from help in understanding how to put your most-needed interactions within reach?