Solarizing Polaroid pos/neg & outdated stock

I asked this question in the B&W Film Forum, but someone here might have some insight as well. Please excuse the cross over, if you've been there and done that.

<p>

I have succeeded in making a polaroid 665 neg solarize by peeling it (post exposure and normal processing) under a 75 watt light bulb, at about 3 inches from the light. It's more like a reversed out line around the edge where shadow meets light (there's a name for that, but it's late.zzzzz....). My problem is it's not very consistent, does anyone have experience achieving this effect? How? please/thank you.

<p>

Phase two, is I'm looking for really old 665 or Type 55 film...like 10 years old, or more, please email me if you have any old stock. Thanks...t