Migrating site from MariaDB to MS SQL 2012
I recommend giving this tool a try. I have used it in the past (to do MSSQL -> MySQL) to setup a datasource for a legacy migration. In your case, you don't need a migration, you just need the db to be in MSSQL format. This is a great litmus test that might save you hours and hours of time.

https://dbconvert.com/mysql/mssql/

It's reasonably priced and worth a shot. If it works fine, you'll move right along.