The only Trixons with the teardrop or shipform lugs that had standard inch sized shells were from 1963, when they transitioned to the ribbed square tank lugs. The mounting hardware was altered in 1956 from the old logo to the new logo. There was obviously some stock to use up because drums exist with the new badge but the old logo on the hardware. This dates this drum to 56 or 57 and they need metric heads. The Trixon equivalent of a 20" shell is actually 19 11/16"( 500mm) and the 22" shell equivalent is 21 21/32"( 550mm). The rare 24 was 23 5/8 (600mm).
You can get 20,22 or 24 hoops to work with standard heads on the kick drums, with some fiddling and the 330mm rack toms are just a smidge under 13", so standard sized heads will work on them but the snares and floortoms are way oversize and require, either custom calf or custom Remo heads.
I have custom Remo heads available, if anyone wants them but they are actually hand made at Remo and the heads are therefore expensive.