Deluge Mode; numeric field not giving actual value

Deluge Mode; numeric field not giving actual value

I am having an issue with a workflow where I have below defined:

sendmail
(
    To       :  " email@email.com" 
    From     :  zoho.adminuserid 
    Subject  :  input.Vessel + "arrived at" 
    Message  :  "" 
    Attachments : template:Arrival_Report as INLINE
)

However, the email notification arrives as below example:

Example: 2912445000000210079arrived at

It seems as in Deluge Mode I can only choose the relevant fields as numeric fields, which would explain why the ID is shown. So question is, how do I choose the field to show the actual value of the field?

The relevant fields are look-up fields which may be the reason?