I’d be really grateful, it’s silver plate, think the base metal is pewter, but not sure. I literally cannot find out anything about this piece other than it’s a porringer or sugar basket! I’ve been through hundreds of hallmarks on a uk silver plate identify data base. Thanks in advance, fingers crossed someone knows!
It’s not surprising that you haven’t found that hallmark, because it isn’t a hallmark. 
The letters are BMEP, standing for Britannia Metal Electro Plate. In short, plated pewter.
The “m” below that might be the initial of a maker, or more probably, a date letter that was used by one maker, but it will probably be impossible to identify. Only sterling, and a few types of silverplate, can be dated with any accuracy. Even sterling can be tough to nail down unless it’s from the U.K. or a few other countries that have a mandated dating system.
And I would say, “sugar bowl.” A porringer would be more shallow, and have a single, flat, horizontal handle. 
Thank you so much Jeff, that was so helpful, I really appreciate it, loads of info there.