I would agree with your 100 gram estimate although I have used one in the past with a charge of up to 120 grams no probs..
I have to wait and see once it gets here.
I'm not quite sure about the electric or gas though.
This was a deal concluded in less then 5 minutes and I didn't want to ask too many questions in case the seller would awaken and start to investigate in order to answer them.
The price was so incredible that I bought it sight unseen and had it removed from the bid site.Time was of the essence as the seller had a previous weekend outing planned and won't be back till after the weekend and I didn't want anyone else to discover it and start a bidding war...
The nice thing about these is that they are built to last and this one looks to be in excellent condition for it's age.