Help with execution plan analysis
Comment out the left join to AppHisTeams as you do not use that table.

Creating indexes tends to be an art, you should not just create indexes. You may be able to adjust existing ones. 

You should index AppHisScanCodes as it is not using one, maybe on scanid and include [Description] or use scanid as the clustered index.

Can you change the left joins to inner joins? Especially to AppHisActivigity, 30,000,000+ rows, as you are only using it to get to AppHisTeams.

Is MOdate a date field or is it a number? 

Can you inner join to AppHisOutput, 20,000,000+ rows?

Look at the existing index IX_AppHis_ABR. Can you add the fields TitleNumber, AppType or IntakeDate with an include statement if they are not in the index already? 

Add an index to AppHisOutput on MODate. Index on abr include modate.