I think there's a fair amount of discussion on what modern Cornish "should" sound like -- and then there's the discrepancy between what people think it should sound like and how they actually speak it. (For example, whether to distinguish between open and close O sounds.)
I think the traditional English of West Penwith is taken by some as a model under the theory that since that is the region where Cornish was spoken as a daily language for longest, the local English may have been influenced most by Cornish, and that this may be our best bet for an authentic Cornish accent. But as for whether the local English was in fact influenced phonetically by Cornish I imagine we have no way of knowing.
In my limited experience, at least the R is usually anglicised (an approximant rather than a trill).