I recently acquired a Holdsworth frame and fork. The seller and I both believe the frame to be a 'Super Mistral' . We are not sure of the year. The frame may have been repainted it's hard to tell but it looks pretty original. The serial number, 36381, on the BB matches the with the serial on the fork steerer tube. There is what is likely an original campy cable quide and the dropouts are campy. Wrap around seat stays.
531 decal but not one I am familiar with. The bottom bracket is english 68mm 1.37 but has lockrings on both sides. Any info appreciated. The frame is very light and very well constructed. Of course the Shimano decals were something added by a previous owner and will be the first things to go. The frame is fully chromed.