The anchor is fine - as long as it will fit nicely in the roller.
I was making a joke about the upside down part

But what I meant is that that is not how an anchor will naturally come up into the roller. The flukes will swing the other way as the shank comes over the roller. WHAT HAPPENS if you pull the anchor in by the windlass as opposed to setting it there by hand? Will the anchor clear the boat?
It looks like you're using a securing pin to keep the anchor there? That's fine, as long as that pin will "stay" secured. But, it would be a good idea to a secondary securment - a tether.
You mentioned "straps"... do you mean metal strapping that is run on the underside of the anchor hatch to secure it better... and it spans across the anchor hatch to the actual deck... and then that space you made is through bolted to the strapping?