hello non fixie en elev 12k

there is nu tubing decal (for so far i understand what that means !!) so in dutch er is geen type vermelding...the only name you can find is RIH. Forgot to mention that on the bottom of the bracket is the number 181. I submit another photograph and the same photograph with the crop of the front. Hope to hear from you it's quite interesting for me. Also include a photo from a RIH cove...the lugs look the same but for the rest the frame and parts look much younger. By the way I believe that this RIH cove is handbuild..
If you take a good look the lugs used for the headpost are the same as mine. The fork is totally different...also the letters used for RIH are much more modern. The fork is quite straight also in contrast with mine which is much more curved.Quite a mystery. Also heard from somebody at the forum VintageR that the RIH cove did not had Amsterdam written on the the blue RIH plate at the headsets...but RIH Holland