Long-distance teleoperation will enable forthcoming scientific and commercial developments on the lunar surface such as in-situ resource utilisation. However, the large distances involved in these applications introduce multi-second signal delays, which may impair user performance and lead to reduced trust in the system. This work presents a user study of 26 participants exploring the impact of open-loop model-mediated teleoperation (MMT) in providing real-time feedback alongside a delayed video stream of the remote regolith simulant sample collection task. In this system, an imperfect but computationally efficient model was employed to visuo-haptically render the simulant. Three conditions were examined: MMT with visual feedback, MMT with visuo-haptic feedback, and direct teleoperation with delayed visual feedback. Users reported greater trust scores in the visual and visual-haptic MMT conditions (+13%, +12%, respectively) compared with delayed direct teleoperation. In addition, they demonstrated more trusting behaviour in the MMT conditions by reducing the duration of 'wait' periods. Performance metrics were also improved in the MMT conditions (faster completion time), although no significant differences were observed between the two MMT feedback types. These results suggest that, despite using an approximate representation of a complex environment, MMT is a valuable tool for improving performance and developing trust in delayed teleoperation systems.