Your Benji is darling!!! I'm so sorry you lost him.. it is a terrible heartache!
You might want to look into a rescue... I've found it to be a fantastic experience!
My Quincy is all maltese but apparently the 'dad' was from a New Zealand breeder ( If I recall correctly) and was bred to be of 'sturdier' stock. He's short legged, and short body but his structure is very 'rotund' meaning his ribcage is quite 'rounded'. He weighs 13 pounds+ .
Now Naddie ( heritage unknown) is abt the same weight give or take a few ounces yet she is structurally much leaner/longer, and longer legged. She looks 2x his size yet they only vary in weight by a few ounces.
It has been thought Naddie is Maltese mixed with either bichon or havanese.
The photo shows the difference in size ( yet weight not that different)