Probable mechanism of enzyme evolution: how did EBG of E. coli originate?

A mechanism is proposed for the formation of Ebg-evolved beta galactosidase-of E. coli based on the following assumptions: 1. In the presence of lactose, certain proteins being translated bind to their m-RNA-ribosome complexes; 2. This binding interferes with the release of m-RNA from the bacterial chromosome, marking the gene; 3. Thereupon a cytosine specific methylase and methyl cytosine deaminase pair, modify - mutate - the marked gene; 4. The result, after five or so mutations, is a new gene capable of coding for a different protein which can split lactose; 5. I propose that this enzyme pair has evolved to produce mutations internally, when need arises, as is the case here; 6. This may be a general mechanism through which drug resistance and detoxification of a novel chemical, could be achieved in bacteria; 7. All of these ideas are experimentally testable.