What a beauty! It’s certainly chock-full of contradictions…
I would put its age as late 1880s/early 1890s - but, as you’ll know, this is not an exact science and I would be delighted to be put right on this. The rounded handle and collar are both indications of an early frame but, as I have discovered to my chagrin in the past, these features persisted well into the 1890s on certain rackets. The head shape and size and the scalloped wedge are both, to my mind, suggestive of an 1880s racket at the absolute earliest. I am struggling to recall a straight-headed 1870s racket that didn’t have a concave wedge and that wasn’t significantly less substantial than your fantastic example.
The full leather grip is really quite something. This kind of binding was the preserve of real/court tennis rackets so the manufacturer may have been in that business too or had access to a lot of cheap leather (whereabouts are you based, if you don’t mind me asking?). Alternatively the racket’s owner might have done it, I suppose? As you say, it’s pretty seamless so, if the owner had slapped it on, they must have known what they were doing. Leather, rubber and surgical tape were all used back then by players who wanted a bit more traction than was afforded by the combed wood.