Weinmann 610 centrepull, fitted with cartridge type V-blocks and non-standard mounting nuts etc., MA2 rim.
The spacing of the brake blocks is as per my earlier post, i.e. so that the caliper only opens a little wider than the rim. To make this work as well as possible, I machined the bases of some domed nuts, so that they replaced one of the concave washers in the standard mounting. I also added some washers where the brake block bears against the brake arms; the curved washers are small diameter and the slot in the arms is of a generous width, which didn't seem quite right without such washers. If you don't need to adjust the toe-in, a simpler arrangement of spacers is possible.
These calipers are paired with weinmann non-aero dropped bar brake levers but some shimano ones (that originally were used with side-pulls, rather than DPs) will also work well if you want an aero lever. There are flat bar levers that have the correct MA for using with this type of caliper too.
These brakes are good; as good as a rim brake gets, pretty much.
cheers