Does anyone know of an updated and complete list of colleges that offer scholarships for National Merit Finalists?
This is a good starter site. In addition I would look at the discussion for the year your student is graduating Example National merit 2018 etc.
Be aware that colleges can and do change their scholarships from year to year. Updated information is usually released on the college’s web site the end of August/early September so even if you check now you’ll need to verify the information in a few months.
If you let people know what type of school/major you are looking for people might be able to point you to schools known to offer $$ NM scholarships in the past.