Trust me im being conservative in funds on this one. Thanks for the links I did think about the dia compe as the brakes are all dia compe but I didnt like the name branding. I managed to get the SM one type for £9.00you did take the expensive option though.
https://www.sjscycles.co.uk/headsets/jtek-top-cap-and-star-nut-with-guide-for-brakedynamohose/
https://slam69.co.uk/products/gusset-hole-in-the-head-hollow-star-nut
https://slam69.co.uk/products/dia-compe-hollow-top-cap-star-nut-set
Old BMX were meant to be heavy, they were built hard for a reason.
stuff like the gyro can be replaced for dirt cheap.
everything else, dip it in