Bathtub drain replacement difficulty
I have a roughly 50 yr old house and am trying to replace the drain in the bathtub. It is rather old and a little but rusty. There are 2 crossmembers, so I think it can be unscrewed with a tub drain wrench. However, I have not been able to get it to turn with a drain wrench and scrwdriver.
Can anyone confirm that this type of drain is removable by unscrewing and is not a permanent part of the tub?
If it can be removed is there a way to make the job easier? If it is old and rusty is there a way to loosen it up more? I have tried cleaning it with CRL and applied a little bit of WD40 but this hasn't worked.
I attached pictures of the drain and the tools I'm using.