ANTLR v4 data file format parser

We use a legacy text data file format from the 1980s for storing scientific data. Each file is typically 10kB to 1MB in size (usually at the small end of this range). We need a converter program to convert these old files (we have thousands of them) to XML, a newer, more maintainable format. The old format has a very detailed definition document giving the definition in extended Backus-Naur form (EBNF) as defined in ISO14977. We can supply detailed documents describing the format, skeleton parsing programs from the 1980s for illustration, and many sample "known good" data files. It seems sensible to have an Antlr v4 parser to read the legacy file and produce a program (in Java perhaps) that will write the data into an XML file. So this project needs someone familiar with Antlr to write one for us. The final deliverable would be that Antlr parser, following all the EBNF definition of the legacy file format. We are happy to send the definition documents so that you can assess the size of this task before you commit to it. We are not under strong time constraints - this could be done over the next 2 months.