Good point - I hope that turns out to be the case. As I mentioned, I'm hoping that having such a stunningly accurate headsculpt as the Ray one next to Peter will improve it by association (along with walkie-talkie partly covering Peter's face). But if it's as simple as unzipping the top a bit to show more neck then I'll be ecstatic.
Currently, the Venkman sculpt looks very What About Bob, Scrooged or maybe - being very generous - GB2. Older, chubbier. There's a decent dose of Murray, but it's a very round/chubby look, not his leaner GB1 look. I do think a key issue is the 5 o'clock shadow - which shows on Murray clearly - isn't very noticeable on the BW head, along with his pockmarks.
I think I'll always wish it had been nailed like the 1/4 scale Venkman, which is a really great likeness (albeit slightly caricatured)...