According to this scan (cadged here – http://equusbicycle.com/bike/zeus/zeus85/index.html) my own 1985 Razesa bike has probably got English threading at the bottom bracket. This is good news. I will order the Shimano 600 crankset for square taper bottom bracket and be able to install those axe-head MKS Lambda pedals. The image below a legible cutout of the bottom of the page that appears above.
Christov_Tenn 