How about adding a V3 or V5 PCI as a second monitor device? Most good LCD's have VGA and DVI inputs, you could run the 3dfx board to the second input and enjoy.

The wrapper is nice but some games don't play well nor does it look the same as running actual voodoo hardware IMHO.

There are a number of Red Baron sites with information that might be of interest:

http://www.wings-of-valor.net/files/documents/xpworkarounds.pdf
http://newbie.wings-of-valor.net/
http://swwisa.net/resources/newbie.html

Well, there will be advantages and disadvantages to both approaches.  Unfortunately, I am still strictly "old school" in my approach, so I can't really comment on what to expect on modern hardware.  I have the following machines that I use for gaming:

GAMEBOX1
Soyo SY-7VBA133U Motherboard
Intel Pentium III 933 MHz CPU
256 MB SDRAM
Seagate 120GB Hard Disk Drive 7200 RPM
Creative Labs Sound Blaster Live! Platinum
3dfx Voodoo5 5500 AGP Graphics Adapter (OEM)
Windows 98 SE

GAMEBOX2
Soyo SY-7VCAE Motherboard
Intel Pentium III 933 MHZ CPU (OEM)
512 MB SDRAM
Seagate 80GB Hard Disk Drive 7200 RPM
Creative Labs Sound Blaster Live! Platinum 5.1
Visiontek GeForce4 Ti-4200 Graphics Adapter (OEM)
Windows 98 SE

GAMEBOX1 is configured for Glide games, and I had Red Baron 3D and Grand Prix Legends particularly in mind when I built it.  Even so, it is not a panacea when it comes to playing Glide titles.  Voodoo5 5500 has a problem in Red Baron 3D where the game crashes to the desktop at the end of Fly Now missions when the desktop resolution is the same as the in-game resolution.  The workaround is to make the two resolutions different.  However, this was not an issue when playing the game on a 233 MHz Pentium MMX machine with a Voodoo2 adapter.

GAMEBOX2 is configured to play more recent games (i.e., 2002-2005) that require a GeForce or ATI card.  I have tried Red Baron 3D in this configuration with a Glide Wrapper, but there is quite a performance hit.  With GAMEBOX1 I usually get about 60-80 FPS in Glide mode, but it drops to about 20-40 FPS on GAMEBOX2.  So if you are going to use a Glide wrapper, you definitely need a much faster configuration to compensate for the performance hit (assuming you demand the same level of performance).

Soyo has stopped manufacturing motherboards entirely, so I can relate to your frustration with trying to get parts.  I built GAMEBOX1 and GAMEBOX2 back in 2001.  I don't think I would be willing to spend the time required to gather the parts for such machines today, and I would be reluctant to get used parts for such machines in any event.

If you can't get an answer to your question about Over Flanders Fields in this forum, you might consider asking at SimHQ in the Over Flanders Fields sub-forum:

http://www.simhq.com/forum/ubbthreads.php