After adding a few more details, like the forward facing hooks, the metal bands on the wheels, etc., the build phase of the chariot is done.
To finish the saddle, I covered Fleabite Worm with a sheet of clingfoil, onto which I then pressed green stuff at the front and back. This way I hoped to press the greenstuff into the model's contour, providing more adherence and stability, while being able to take the cured green stuff off the foil, preventing it to stick to the wyvern.
At the back, I added a banner pole using a toothpick.
At the front, I added a saddle horn. In the kitchen we use wet wipes for quickly cleaning small spills etc., and had a rest which had dried up. Of course I kept these for future hobby use. I cut some strips from the (now) dry wipes and placed them around the saddle, then drenched them in thinned modge podge with a bit of added iso. The wipes, I thought, would be easily bendable into shape once drenched and therefore being heavily hanging down, but they were surprisingly resistant.
In three layers/sessions I achieved the desired effect. Taking everything off the clingfoil also worked well.
I prepared a piece of chain. Around the ends I looped twine, which I then drenched in superglue.
The idea is to glue the chain to the saddle horn once everything is painted. The ends with the twine can be loosely hung on the horns at the wyvern's head. This allows for the removal of the magnetized rider, while adding one more visual attachment point to the wyvern.