Before looking for a replacement, think about your instrument. Not all cover plates are the same. What do I mean? Not all instruments models are the same.
My OMI cover plate cannot match any modern spacing. Invariably, several holes don’t line up. Then a quandary happens. Modify the instrument or the cover plate? ISO 9001, Deming, and QC are modern guides.
The past is fraught with guesswork and approximations. An instrument wasn’t expected to be bling’d out. It is its own unique setup. If worn out, buy a new one. Consider carefully.
As far as I am aware the Beard & OMI coverplates mounting is identical. It gets MUCH dicier with many imports. The pattern is slightly different and the mounting holes use a smaller sized screw.
As far as the Lotus plate, I've found it to be the most restrictive design in terms of acoustic projection. It was designed before Paul started to use sophisticated calculations which involved open/closed spaces and space positioning.
I don't have the knowledge or experience that Howard has about the development of the lotus coverplate, but I concurrently owned two Beard Mike Auldridge instruments - an early (black) model with standard coverplate, and a later one (red sunburst) with the lotus. The lotus never had the astonishing sound quality of the older version. Not even close. I never considered that it might be a function of the coverplate, and blamed it instead on the difference in finish.