Any Olympus Pen experts?

A local goodwill has a PEN that I can't quite ID. It has a 28/3.5 lens, no meter at all, and the back swings open (doesn't come off completely) like a Pen S.

Any ideas on what model this might be?

Thanks!

There is a really useful website floating around in cyberspace which details all the Pen models, but I can't recall the URL. A google search should find it.

http://www.camerapedia.org/wiki/Olympus_Pen If you haven't been here already, this is usually the first place I go

cheers!

Could it be a Pen EF? Was it black? The original Pens up through the D series all had removable backs.

Turns out it is an EE2 with fixed 1/40th shutter, but 3.5 to 22 28/3.5 lens, very interesting camera, can't wait to see results!!

Here are some samples from the EE2 with Reala 100 film (setting was 64, film is long expired, but refrigerated):

here