There will be no problem fitting a 10 series subframe to a 6748 tractor.
What model Veto loader are you buying ? If it is an early FX series, i strongly recommend welding two pieces of flatbar, 50x10 mm over th entire length of the front part of the boom, both upper and lower sides.
I use a Veto FX 12 loader on a 5245, and when i bought this loader, it was all cracked. It is undoubtedly NOT built for 4WD power. I welded mine with 6 meter of 50x10 mm flatbar, St 52.3 quality. According to my structural calculations, this improves the bend resistance with 71%
The newer Veto loaders are copies of Quicke loaders, after Quicke bought Veto from Thrige agro, those will be strong enough