Magento – Magento How to change product availability text

I have Magento 1.9 with Fortis II theme.
I need to change the "Availability: In stock" text to "Availability: Available. Will be shipped in 3 working days" and the relevant translations.
I have found and changed accordingly all references of these phrase in Mage_Catalog.csv and in translate.csv which should be applied after the core settings, but nothing happened. Searching fo an answer in the forums I found a relevant topic with an answer about core_translation database table. I have searched this table but no reference found.
So, ho am I going to set the availability text as needed?
Further more, there are products that are available in stock, other products with an aailabity of 3 working days, other on 10 and other are available on order. How ca I set all those availability statuses?

Thank you