Hi Gordon,
If you can get a look at Len Mason’s book, Using the Small Lathe, there is a line drawing of how he made his, and which I followed, suitable modified for my lathe.
Essentially, mine consists of a 6mm x 30mm x 80mm plate with a slot machined lengthwise slightly less than the file thickness (in my case – for a hacksaw blade it would be just under the blade thickness) and then a 3mm x 30mm x 80mm clamp plate holding it together. Clamp screws were 6 off 4BA. On the other side of the 6mm plate is a longitudinal thick bar which fits under the toolpost screws and is set to get the cutting point of the tip as near as possible on centre height.
Regards,
Peter G. Shaw