I'd probably say no because I have heard of people finding Further Maths difficult having got A*'s in A-level Maths and the fact that you got A's in the modules suggests you would struggle and my sister got an A at GCSE and a D at AS Maths never mind Further Maths
.However, I would still recommend you to look at the content of A-level Maths and see if you find it very interesting, if it doesn't seem too appealing I wouldn't bother but if it looks interesting then you will probably end up being prepared to work hard for it.
When I looked up A-level Maths and some of A-Level Further Maths I found that the content was far more enjoyable than anything I'd studied at GCSE-in Further Maths you will get to study the Square Root of -1 which is known as i and you'll get to learn about hyperbolic trigonometry where sinh(x)=e^x-e^-x/2 and cosh(x)=e^x+e^-x/2 and if you are wondering why this would have been done then look no further than the formulas for sin(x) and cos(x) in radians 2pi radians=360 degrees sinx=e^ix-e^-ix/2i cosx=e^ix+e^-ix/2 its all extremely mad and interesting.
After the courses, you will become a robot saying"I must integrate.I must differentiate"-I'm only joking
I would love you to take Further Maths though because I'm obsessed with Maths and am taking A-Levels in Maths and Further Maths.