Hi Tim,
Thank you very much for the proper details, it helped me a lot.
I have looked at the template, and those fields does not look exactly like post meta, rather some sort of custom data. However I found that, there was a very simlple way of getting the property data, so I constructed and inserted an additional code the functions.php file in the child theme directory. That code will make sure to obtain and include this information during the indexing process.
Please note that this is sort-of a customization, so I cannot guarantee that this will work in all cases at all times.
For future reference, this is the code I have insterted to the functions.php, please leave it there. It will work with future updates of course.
I re-indexed the database, now it should give results to the keywords from these fields as well.