I would love to share my 775 build with you guys! It's named "DiskWizard 2" after its older brother (a 478 PC) and I use it mostly for BF1942/modding, CAD, and formatting/exploring Hard drives. I run dual boot WinXP x86 and x64 for massive compatibility. Here's the Skinny:

Motherboard : ASUS P5N-D (needs replacement, ever since I got it in 2013-ish? the memory controller was damaged, maxes out at 3GB, boo)
CPU: Pentium D 960 3.6Ghz running with 233MHZ bclk (1.4V core stabilized)
Cooler:Zalman CNPS9700 with a Deepcool NB 8 on the NB
Memory: Patriot DDR2-800 2GB stick(s) x2 (777Mhz @4-4-4-12) @2.1V
GPU: This is a tale of woe right now. I wanted my XFX 9800GT in there, but it died suddenly while rebooting after installing drivers. SO...
GPU: EVGA 460GTX with 2GB memory
Sound Card: Sound Blaster Audigy OG (no Dell P/n, woot)
PSU: Corsair AX850
HDD: 60GB Western Digital noise maker™ deluxe(x86) and a Patriot P210 SSD(x64)
FDD:Teac FD-235HF (newer model, from 2006)
CD/DVD: LG MODISC series and Optiarc Super-Multi with Litescribe
Case: Full one-off custom ATX.

I started this build wanting a PC-60, but didn't have another, so THIS is the best I had. It was yellow, and I mean YELLOW, so that had to go. It had NO airflow, as you'd expect for a 1999 PC, but I had a real bug one day and went way overboard doing-it-up. I have two Cougar fans doing all the work in there and it moves PLENTY of air, though the thing is basically a space-heater, 🤣

The most difficult part of this whole ordeal was modifying the case for modern cooling. I always get anxious about "ruining" vintage gear, but it was something I really wanted (and wasn't going to cost me anything, 🤣) so I started drawing all about and cutting here and there.

The final product is a vintage MASTERPIECE I wish I could've build back in 2012-ish. Strange vibes emanate from the meshing of late 00's BLACK and the beige-ness of the 90s. I polished the metal on the inside, just to make it POP. I must say, it really does.

-Peace and Love!