A quick perusal of Ebay reveals TWL was Hi-Fi on VHS, but has the dreaded "home video version" on the back, which used to mean some music on the soundtrack may have been replaced.
Private School only seems to have Dolby NR visible on the labels. (MCA Home Video) There is a later version with the MCA/Universal home video logo on the box that would be more likely to have Hi-Fi tracks.
Anything reissued on the Goodtimes video labels should be avoided. (Universal farmed out a lot of bargain bin titles to them.) The tapes I got from them usually were recorded in the six hour SLP speed, and had poor tracking and usually no Hi-Fi.
Beta Hi-Fi tapes would be in a lot better shape at this point, if copies could be found.