No you don’t need another test.
There are new treatments available for hep c that are much better tolerated and very effective vs the old interferon treatments. Your dad should get treated and cured. The new meds have cure rates as high as 99%
You should not borrow AMF your dad should not lend personal hygiene products like razors, fingernail clippers or tooth brushes. While the risk of transmission is very very small when sharing these personal items there is still a non zero risk and should be avoided.
Check with your dad about him getting treated. His treatment could be as simple as one pill a day for as few as 8 to 12 weeks and he could be cured.
Best of luck to you both