Observations of the rotational spectrum of lead monofluoride, PbF, have been extended up to transitions in the v = 7 level for PbF208 in the lowest X1Π1/22 state of the radical and v = 5 for the Pb207 and Pb206 isotopologs. The data also include a few measurements for PbF204 at v = 0. These new measurements have been combined with existing near-IR measurements of the X2-X1 fine-structure transition and a simultaneous multi-isotope fit of the data to an effective isotope-independent rovibronic Hamiltonian has been carried out. The resulting parameters fully characterize the vibrational, rotational, and hyperfine structure of the combined X1/X2 state of the radical. A pair of opposite-parity levels with total angular momentum quantum number, F=1/2, in the lowest rotational level, J=1/2, of PbF207 are close in energy and their spacing decreases with vibrational excitation. The experimental results show the spacing decreases to less than 20 MHz at v=7 and 8. The experimental work is complemented by new ab initio calculations which support the results and allow predictions outside the experimental data range. The calculated radiative lifetimes of the relevant vibrationally excited states are of the order of 50 ms. This paper was motivated by interest in using PbF207 as a vehicle for future probes of the standard model of physics such as placing limits on the electrons electric dipole moment (eEDM), eEDM calibration, molecular charge-parity nonconservation, and Born-Oppenheimer breakdown effects for example. © 2024 American Physical Society.