If you look around this site a little you will find a little info on Mappin and Webb here Mappin & Webb "The Celebrated Hollow Ground" 11/16 - Straight Razor Place Wiki . Pairs and sets of multiple razors are seen less often than single razors so you may have to be patient in your e-bay searching for them to show up.

If you think they are sharp enough to shave with as is then have at her, you'll know soon enough if they aren't. If you find they aren't sharp enough you could always try to hone them up on the old stones. I don't think anyone on this forum would advise doing either for a beginner who has never shaved with a straight razor and I am certainly NOT doing so, that was meant tongue in cheek. You are certainly free to ignore any well meaning advice given.

There is a ton of info here and if you wade through it most of your questions will be answered.

Bob