No don't go to Bunnings , they will not have the correct screws in stock because being USA made they will be an SAE thread in imperial size ( different again to the English UNC/UNF threads , but the same diameters ) , Bunnings don't stock SAE and the person you deal with will probably look at you like you are from another PLANET .. .
I know this because I had a FT focuser and my made in the USA CI-700 mount is all SAE as well .
It looks like someone
forced a close metric bolt in , has it damaged the focuser threads ? .
Any good machinist will have the gear to measure the thread and point you onto a good supplier , they will sell small lots if you take the focuser with you .
Good luck .
Brian.
ps. you will need an imperial allen key set as well