Hey Phil,
Because those guards are integrated for OE honda hardbags, they are a pretty convoluted design. Finding someone in Ireland with a tourer or interstate would probably be a big help.
I was just thinking,
Champion (Trikes) in California makes the best aftermarket fiberglass hardbags for Valks, bar none (Patriots). They used to sell a heavy bar bag guard to protect those bags on a Valk, but are long discontinued, and impossible to find used. I think they would be much easier to duplicate than the honda guards.
Champion has a rep for being hard to deal with or get replies from, if at all. But an email to them asking for a copy of the design of those bars might get you something you could take to a welder. Their guards were horizontal (more traditional) than the vertical style of the honda guards. The other issue would be whether those bars would clear or interfere with the position you have your Givi's mounted at present.
It is too bad they were discontinued because everyone with a hardbag standard ought to want a pair.
They have a toll free number.
http://www.championsidecars.com/default.asphttp://www.championsidecars.com/products.asp?scPage=3&catID=7&itemID=312


Super tight fit with Honda bags.
