Your 10mm bolt casing should be better than the 8mm, it always favorable to build on later case if can so that worked out well .
Stratcher brace is potentially good but I think need precise skilled welding be excellent, thick build up of matting & resin around nose & end packed with resin/swarf with a thick steel or alloy plate bolted on end works, was done on bluebirds, russians, kiwis & oz boys done this & also brace idea similar to stratcher, his just a more precise fit evolution of the early ones, is a thread on here with some pics of early brace ideas .
Have fun building up some break-in miles, will be nice be back in a mans car and shot of that old faggy honda :-)
When you here her running & feel the potential of the car again the cash & hassle will seem worth it .
Expect you fitted it faster than I typed this lol . have fun with your new cogs ...