My passport Essential 500gb opened -> now 2TB

A friend of mine has a passport essential 500gb.

Some days ago it started showing up as unformatted. As an action in panic, he opened the disc and removed the platters with the intention to put them in another disc (no comment on that one please).

I told him to put them back. I don’t know about dust treatment or anti-static measures etc. I don’t suspect any.

So to the point, when he connects the disc, it shows up now as 2000+gb (I don’t remember the exact number, but it wasn’t 2048). It there any (extremely optimistic) chance that we see the disc and get the data with some data rescuing tool?

The disc spins up correctly (as I could hear over skype and as he told me), no click-of-death or other malfunctioning (at least audible).

Next step is a data rescuing company, but we’d like to give it a try since the first quoted price was 700-1500€.

Thanks in advance,

Alexandros

Edit: Since the problem started, the disc would show up as unknown device (“This device did not function properly and windows don’t recognise it” or something along these lines). It still shows up this way. Any idea why that? Win7 x64. When I open the device manager though I read product ID (PID)  070A, and a Vendor ID (VID)  1058 (Western Digital).