Melocacti taxonomy is hard even with cephalium developed.Without it, it is many times impossible.
Hybrids sold worldwide make things even worse.
Most of Melocacti sold are matanzanus, since they are maybe the easiest of the genus for one to grow.
One of my Melocacti, looking very much like yours, is every summer a very prolific fruit producer, with wonderfull coloured lilac-pink fruits popping out of the cephalium without stop, over a long time.
The problem is ...that I've never been able to see the flowers. On my matanzanus I could, they emerge from the cephalium. I will look again closely this year(anytime soon) for any sign of flowers, but I'm pretty sure I won't see any!
I recently understood why, after reading George Thomson's book about Melocacti.
In two species, M. neryi(the one I've got) and M. lanssensianus, the flowers remain hidden inside the cephalium.
This characteristic enabled me to name my Melocactus at last!
).
. Nice plant