What cutting tools to use on a Boxford 125 TCL with turret?

[m_c]

The modern equivalent for a A08MSEUPL06, would be a A08H SEUPL 06, however the 08 means it's a 8mm diameter boring bar. A 10mm would start with A10, and use a larger size insert, however it could of been a custom holder for Boxford.

Personally, I'd suggest a SCLCR/L (the final R/L dictates left or right handed) style boring bar, which will use CCMT0602 inserts. Also get the same style turning holders, as it means everything will use the same style insert. CCMT inserts are a reasonably good all rounder, although you may want to consider some holders that use DCMT inserts, as the sharper point can be useful for certain profiles.

However, the vast majority of turning will use a right hand tool, as most material removal is done working toward the chuck. I personally can't remember the last time I used a left hand tool to work away from the chuck.
A good part off tool is always good to have, however a MDT (multi-direction tool)/grooving tool can part, work up to shoulders from most approach angles, and do general profiling work, albeit with a limited depth of cut/material removal rate, but I'm not sure what MDT tools are available with 10mm shanks.
In fact Arc have something suitable - http://www.arceurotrade.co.uk/Catalo...g-Tool-Holders

If you were to purchase a right hand turning tool (you might actually need a left hand, as I'm not sure how the tools mount in relation to the work piece on a TCL - you need whatever allows you to remove metal as you move towards the chuck), something like the grooving tool I've linked to, an 8mm boring bar, and some assorted drills (the 8mm bar will need a minimum 10mm hole to get started), those will be more than enough to get you going.

For threading, you might struggle to get indexable holders for threading inserts with a 10mm shank. If so, it'll have to be ground HSS or brazed carbide tooling, with a suitable profile ground on. However have a search/browse of the more hobbyist suppliers to see what you can find. In the UK ARC, Chronos, Warco, Greenwood (just had a look and they do a 10mm shank threading tool - http://www.greenwood-tools.co.uk/shopscr111.html) come to mind as having reasonable quality turning tools.

The problem you'll have is the common smallest size for industrial tooling is now 16mm, although most suppliers will still go down to 12mm. Anything smaller is for specialist machines, and usually comes with an inflated price tag from industrial suppliers, so you'll have to concentrate on the hobby market for 10mm tooling.