Nearly there but completely stuck on:
4a - accountant with vigour granted convertible -??? R?????
11a - fair old place - E???S?????
23a - at home, novelist's hidden impropriety -??? E?O?U? (indecorum?)
3d - sea snake, one in prison! -????? A?
5d - spoils play -????
19d - fashion knight for large bank -? O???
Any tips or help much appreciated. Thanks :)