I have an older place than your, Victorian.
It overlooks a valley and the prevailing weather comes across the valley, causing weathering of the front elevation windows more than the back which are sheltered.
I have several windows at the front restored and modern methods applied to the beads (they basically put the tufty bead in the wooden battens to make a better seal and reduce wood on wood contact which caused rattles / draughts etc).
This was about 8 years ago and all of them look like they need redoing or replacing.
I am thinking about replacing the whole lot with some of the textured finish UPVC as I think it will last longer / save draughts and energy.
There is a local manufacturer to me – Quickslide in Brighouse, West Yorkshire – probably will look to get them to do the whole lot.
HTH
Alastair
PS one issue you will have if you don’t go sash of some sort it either back filling or front filling the gaps as a sash window is kind of 2 windows back to back. If you replace with one window you will have an internal gap to fill or potentially a problem on the outside if you position on the internal side