Pewter with the slight lead content might be save to use for just eating out of, as well as the old enemal-wear if it contains lead, but I will not risk it. As for the longer time of cooking esp. an acid food I would be very wary. (Read old coffee pot here)
An incedent in 2002 brought this to my attention in spades. I went to a 3 day event and when I got there I had forgot the enemal-ware coffee cups. I did have a tin one of unknown origin, but it was old, my Grandmother had gave it to me, it came off a farm sale over 50 years ago. Well I drank lots of coffee and Gatorade that weekend (read acid) About three weeks later I ended up in the hospital with my gastro problems, well the first thing we did was a heavy metals test. It was below the danger point, but higher than I have ever seen before.
I had not done any casting or work on the indoor range that summer, the lead has never been as high again. My doctor and my corpman friend Matt and I all agreed that the most likely source was the tin cup, no retired and never in the camp gear.
Any one reloading, casting, doing ren-actments and such owes it to themselves to have a heavy metals test at least once a year, this was an OSHA requirement when I painted for a living and a practice I still follow. My doctor has had no problem slipping them in anytime I have GI problems or when I have a physical, the insurance company has never bawked.