You will have to match rail heights between the Tillig code 82, and Peco code 75. Probably just a bit of careful packing and some experimentation with the Peco and Tillig rail joiners to find a means of adjustment so that the rail tops match perfectly for height.
As an example I join code 75 SMP to Peco code 100 used in the 'off-scene' areas, by crushing flat one half of a code 100 rail joiner, and soldering half a code 75 joiner on top of the crushed section. Sounds crude but it does the job. A similar technique can probably be devised for the combination you propose.
If only there was mixed gauge track in the UK. Very tempted by the Tillig dual gauge stuff, particularly the chance to incorporate a sway.
As an example I join code 75 SMP to Peco code 100 used in the 'off-scene' areas, by crushing flat one half of a code 100 rail joiner, and soldering half a code 75 joiner on top of the crushed section. Sounds crude but it does the job. A similar technique can probably be devised for the combination you propose.
If only there was mixed gauge track in the UK. Very tempted by the Tillig dual gauge stuff, particularly the chance to incorporate a sway.