Enquiring if anyone knows of an online store, or bolt shop in Melbourne, that have these.

I have tried one bolt shop but the length is a little shorter than the original. There is only enough thread left for the nut if leaving off the spring washer.
E-bay listings seem to be for imperial bolts and enquiries on those reveal they only are available up to 5.5 inches. The originals I have are 6.25 inches (about 158mm)

Any guidance/advice will be appreciated.

Thanks,
Steve