Sorry, I reached second level of JSW3 about 4 years ago, then I didn't play the game at all.
(It is because exactly that game cannot be classified into "Jet Set Willy" type
due to some features which original JSW doesn't have.)
IMO, I can recommend everyone to play JSW3 itself
because the game is simply nice PD.
For example, a green centipede in the 2nd level is fantastic.
IIRC, JSW3 is included in Assassins CD 2.
AmigaFuture also archives ADF version.