Agreed on changing the pk to clustered.
Can't tell without lots of analysis, but single column nonclustered indexes are typically not very useful. Maybe check how often those are used?
The index isel1_dx should be widened as follows:
Index key: (assyst_usr_id, isel_name, field_name)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability