" Simply pushing the connector plugs through the back of the box released the drive from its housing and it slid out the other (open) end completely exposed and unprotected - platters, spindle, heads etc were there for all to see!"
I cannot credit that the hard drive was open to the outside world.
I was using "standard" HDs of various manufacturers from about the late 1980s onwards and before that had Tandy TRSDOS II with an external HD which was huge, very heavy and had to be switched on for one minute before booting the computer. All this for 4Mb and £2900.
My point is, that from the earliest Winchester drives the whole thing had to be sealed from outside dust et. etc. on pain of crashed heads.
While HDs have a memory which seems to expand exponentially their outside appearance and dimensions haven't seen much change until the advent of the laptop when 3.5" drives became the norm.
I suspect that Tiny fitted a normal IDE drive (perhaps in a cradle) of whatever make gave them a good price.