A glazier would generally charge higher but you can always ask them for a quotation. If you know a credible DIY guy who's capable of doing the job, I suggest you should go there.
Agreed. Based on the photos, re-puttying will get the job done. I wouldn't advice replacing the windows. The new ones might not suit the overall design of the house.
Even though there are lots of window replacement companies out there, not all of them can maintain the character of the former window. While there are few of them who can manage to restore the window's old glory, most of them come at a hefty price. You can www.windowinfo.co.uk/ to ask for a free...