i bought a fully enclosed rear chainguard for the a10 a year or two back, i did nothing with it apart from paint it , it is an original bsa one and not a reproduction so should fit perfectly, i know how the thing fits aprt from the very front section , i have looked in the useless haynes manual and it was no help. can anyone tell me how or what it attaches to ? the only thing i can see is two small tubes that run across the front section. do i have to drill the engine plates for bolts ?