The seller didn’t post a photo of the barrel flats. This is such a common mistake these days that I usually suspect he has something to hide. I’m usually not wrong, either. If it was reproofed in England, the flats would tell us that. If it is a shoe lump gun, we could see that. The length of the original chambers will be there, as well as any other alterations that were done in England.
I’m not sure a shoe lump is a reason to dismiss a gun out of hand, or, for that matter, to insist on a gun having that feature. Look around long enough, and you’ll find broken guns with barrel construction of all different types. Ditto the drop lock feature. Cool, but, so what?
I’m not the expert, but, 1933 seems like it might be a bit late for model C leverwork. Someone will know. The beavertail and the straight stock look like hot pants on a hooker that has been collecting social security for 15 years, out of place. But, if that is specifically what you are looking for, you do you. As to whether the drop lock feature is worth the premium in price on what is a 12 gauge English boxlock with ammunition requirements that are a bit specific, that is going to be your call.
$22K is a bundle.
Best,
Ted