No, you can't just go buy new blades but you can maintain the ones you have indefinitely...with the right tools.
....and OMG that is a lovely item. You have a very nice friend. As far as shave gear goes that is a grail item for many, especially in as good a shape as it is. It is worth some $$ but that's not really the point because we all know you can be given something like that for the price of a pizza and beer, find it at a vintage store for $5 or scour eBay and pay any amount you are willing. So When I say it's "worth" a lot I mean it is hard to find and harder to find in good condition that you can enjoy using...because when you have that thing (those blades) ready to go you will love the shaves. They shave like a straight razor because the blade is essentially a straight razor blade with a handle.
About the razor and blades: you will see others like it, under a different name or same name but they don't ALL have 7 day sets and they don't all use the exact same blade. Your blades are a little smaller than the others because they slip inside a holder that is then mounted in the razor (am i right? thats what the picture tells me). You would leave them in the holder to strop but would take them out to hone (you would use a different tool to hold the blade for honing, it look like you don't have that BUT it could be inside the handle or under the felt). The strop works a lot like an autostrop, it feeds through the razor..it makes sense once you play with it. Nothing about that razor should be hard to manipulate or turn so if its hard to turn or manipulate you are doing it wrong STOP.
I have several different ones, none with instructions though. I'll dig out the tool(s) that hold the blade for honing so you can see what i mean. Once you see that you can restore a funky blade you can go in search of more blades on ebay. in the mean time get that strop out and work on getting it flat and conditioned.