Vinegar loaf?

......I found some of my Grandma's recipes in a bag of miscellaneous 'stuff' this morning, there's a marked emphasis on cakes and chutney! Think I'll give that vinegar loaf a nostalgic culinary whirl (I can vaguely remember eating it when I was a bairn) but I'm going to have to work out the modern day equivalent of a 'slow oven' because she baked in a coal-fired range with none of that namby pamby thermostatic control stuff, just a manual damper on the flue.......oh, and I might up the 'lard or marg' to the dizzy heights of butter ;-)