Just managed to source a front regulator sphere from my go to supplier in Estonia - hard to find for this model. Had previously used Monroe branded for the 2 front struts. In the process also found another supplier ex Poland that seems to carry a good range of I.F.H.S. spheres. Company is https://bodycar1.com/ and whilst they do not normally send outside of the EU, they can do special delivery via DHL. Freight quote was in the order of 68 Euro for a single sphere. I stuck with Spareto in this instance even though their part brand was lesser known as the freight cost was 33 Euro, sphere cost 55 Euro.