Sort of only half-vintage, but I built one of the homebrew8088.com PCB sets. Ended up filling up all ten slots:
- 20MHz-rated NEC V40, downclocked to 8MHz for compatibility (new build). The crystal is socketed and you can actually get it to limp through to a DOS prompt at 20MHz with enough wait states and a curated choice of cards.
- DMA controller addon card (new build)
- CH375 ISA-to-USB card (new but modified to support faster reads)
- Serial/HD floppy controller (new, kit-built)
- XT-IDE (new, kit-built)
- Combo I/O for parallel/game/two more serial (vintage)
- Clock Card (new, kit-built)
- RTL8109 NIC (NOS)
- RTL3106 SVGA card (vintage, got it used in like 1997)
- Custom SRAM memory card supporting 64k of ROM and filling any holes in the high memory space with UMBs. (new build, actually working on a new revision of the design)
It's not 1000% IBM compatible, but the recent board revisions are pretty compatible with the most important features.