Hi @griffoso ,
LCD screens replacements are available online.Just search for ''Canon EOS Rebel XSi/450D LCD screen part'' to get results for suppliers.
Here’s a link to just one [https://www.ebay.com/itm/New-LCD-Screen-Display-Part-for-CANON-EOS-450D-Rebel-XSi-Kiss-X2-with-backlight-/261001895464|supplier]. It is shown only to give an indication of the price of the part. There may be other suppliers that suit you better.