Hi!
The nails could be a bit shorter. In black piggies it helps to either hold the nails against a source of light to see the quick or to look closely at where the nail starts showing growth marks - that part of the nail is dead and you can cut safely.
But as a guinea pig ages, especially the outer toes in the weight bearing front legs will often splay sideways. In the very old, arthritis can rather twist the toes and nails.
The back legs are more there for propulsion and act as springs at top speed. The weight in them is more on the heel than the toes themselves when sitting.
PS: You may find our forum information resource very interesting and helpful, by the way. We have one of the most comprehensive currently around. You can easiest access it laid out in thematic order via the guides shortcut on the top bar but here is the direct link:
Guinea Pig Care & Information Guides