Sun Ultra 45 chassis is one sexy design. The quality that Sun Microsystems put into this chassis is second to none. I was fortunate to buy a used Ultra 45 chassis from an UK eBay seller and get it shipped to Australia for $100 AUD (then the seller updated the shipping cost to $200+). The empty chassis does not come with the proprietary motherboard tray so I have to workaround by drilling 3 small holes for three 1.8cm L-shaped plastic standoffs (sourced from the CPS2 arcade machine - I guess the brass standoffs that are abundant online can be used too). Here is the video of the mother bound mounting
Mount motherboard:
https://youtu.be/j3xppDQ_MBkNext is to ask my friend to laser cut me an I/O shield plate from a thin metal sheet.
I will update this space as I progress.