I took my working A1000, and tried to hardwire a kickstart 1.3 ROM to the CPU (following instructions I found on Aminet).
That A1000 does not work after that... I had to buy another one off Ebay. I won't be trying that again!
On my 2000HD, which is woefully inadequate for harddisk mounting space, I cardboard and ductaped a harddisk and drilled and wired in a LED next to the others for blinkies.