Add OS's to Grub

[Grizzly]

Hi All

I have just consolidated two old(er) PC's into a slightly newer one, basically 
took the hard drives out of them and put into the new pc, much to my surprise 
Win7 did not complain (much) once I got my router to accept new Mac/IP/PC 
Name(s)

I would like to boot without any extra keying for Boot order, but both Grubs 
only show their own OS´s

Maybe a senior moment but thought grub (it has in past, when I booted from a 
USB HD with Bionic on) found OS´s at boot?

I know that Trusty is coming to EOS so I will be putting Xenial over it

Thoughts ?