Young Budgies Feet/nail Issue

Hi all,

I had 2 budgies both bought as 6 weeks old babys about 5 years ago and unfortunately one passed away about 2 weeks ago.

so i went and picked up 2 new baby budgies with my kids last weekend 

i messed up and didnt follow quarantine procedure at all. yet to late for that now.

i have only just noticed today one of the new birds seems to have an issue with her feet. It may have been there the entire time ive had them i just hadnt noticed.

she uses them fine. doesnt seem to affect her at all. yet one foot is missing a claw all together and the other has one that appears injured or stumped. and also has a similar build up on the back of its leg. 

ive looked up images of bumble feet and it doesn't seem the same and apart from the areas in the photos the rest of the feet look normal from what i can see.

does anyone have ideas as to what it could be. if its serious and what to do?

regards