For a Hecke pair (G, H) and a finite-dimensional representation σ of H on Vσ with finite range we consider a generalised Hecke algebra Hσ(G, H), which we study by embedding the given Hecke pair in a Schlichting completion (Gσ, Hσ) that comes equipped with a continuous extension σ of Hσ. There is a (non-full) projection pσ ∈ Cc(Gσ, B(Vσ)) such that Hσ(G, H) is isomorphic to pσCc(Gσ, B(Vσ))pσ. We study the structure and properties of C * -completions of the generalised Hecke algebra arising from this corner realisation, and via Morita-Fell-Rieffel equivalence we identify, in some cases explicitly, the resulting proper ideals of C * (Gσ, B(Vσ)). By letting σ vary, we can compare these ideals. The main focus is on the case with dim σ = 1 and applications include ax + bgroups and the Heisenberg group.