If me go with A ; Fabricate new tool rest.
I did just that, acquired a length of solid round bar of correct dia for the upright, plus some round stainless approx 2cm 3/4inch dia for the horizontal rest and had it welded to the bar. Local machine shop had the material (off cuts) and did this for me, finished with 4 rests of different lengths at less cost than one from the lathe makers in my case Vicmarc. To make it easy told the welder I was not looking for showroom finish just needed a strong weld ( quicker job for him) not pretty but practical and tool slides on the round bar with ease.