i'm with Frosty on this one
i also noticed the bridge behind the BB & serial number on the dropout!
possibly a Tange made frame, but they made frames & supplied tubing for quite a few different people bitd
the brake plate wasn't such a worry as my KZ1 has a tube, but i know my & all the other Lasers have a plate
i don't think its a Kuwie,but then i only really know about the models i've got!
click the logo in my sig below & browse Jamies site & see if you can find anything similar on there