Came across two massive sets of chinaware. Any info?

I'm an American and a casual collector of English china.
These appear 1970s-ish and would not have any real collectable value. They were not high end nor very expensive when new.
Unfortunately, you'd be lucky to get $50 for each set in my Midwest neck of the woods, IMHO. Still, that's nothing to sneeze at. If it were me, I'd try listing each set on FB Marketplace for $100 and see what happens. Cottagecore enthusiasts may be interested.

 

There are people out there in the world who snip the pretty parts out of old china and pottery dishes with tile cutters and make mosaics and jewelry.

 

There are several ladies in my vicinity who make "flowers" out of stacked dishes on metal rods. They show up in gardens as accents!

 

That's a good use for orphaned saucers. They have zero resale value and often end up under flower pots if they don't go into the skip and thus the landfill. I remember those supermarket giveaway pieces, at least the pieces if not the giveaways themselves. The dishes still turn up in estate sales, yard sales etc. So do S&H pieces, which are now becomming collectible in their own right.

 

You can see from the few pieces on the replacements site that they are not worth a lot. On ebay, they would sell for even less, maybe 1/3 of the price on replacements.
There are none in Sold listings right now.
They have given the Johnson Brothers the inventory code JB139. You can search using that, as it's the only name for the pattern I see.
I don't think you risk much by listing a couple of plates to see if there's any interest in adding to a set someone already has. It's just, for me, a huge hassle to pack and mail breakables for a couple of dollars profit.