Are you sure yours are right and left threads on the 49? You must have the pre-war style hub with the smaller spindle and bearings. These rings are M75 x 1.5 and only made in right hand thread for the newer style hub. I have supplied these to Niemoeller and Werner Karasch. At this point I'd rather let them sell what they have in stock, since they both stepped up and bought a batch.
I could make these earlier ones, but not sure the price would be good just making two. Anyone else need these? By the way, you need to take a close look at your spindles and check for cracks. Have them "magnafluxed" by your machine shop. Both the 1938 and 1939 cars I restored, I converted the front brakes to the 179 Va set up with the thicker spindles and larger hubs for this reason. On my 38 the spindles were cracked and a replacement set were also cracked. Another advantage to this is you get the 40mm brake should in place of the 30 mm. To do this you need brake plates with spindles, shoes, drums and maybe cylinders.