Update on the work I completed in case anyone is interested
During installation selected to connect to an existing database. This failed as the database was a higher version. Installed using a temporary database and then used DBConfig to connect to correct database. This was also the same during Enterprise Manager installation https://www.veeam.com/kb1845
Once installed and Veeam services started I started to change the credentials and input passwords. During this activity one of the domain accounts locked out. Obviously I wasn't quick enough
Tape server failed to connect. Edited registry key on the tape server and restarted the 3 Veeam services https://forums.veeam.com/tape-f29/tape-library-not-recognized-t26138.html
New server is running 2016 and overall the performance improvements appear to be huge especially with memory usage. On the old server when copy jobs were running, the Veeam Backup & Replication server would typically use 100% of the RAM. Now the server is using around 56%. This might be a reason for you to replace your existing server especially if it is running 2008 R2 as mine was.
During the installation and configuration I received a number of job failures and restarting the services didn't resolve them . Rebooted the server and all OK