Whatever you may do, definitely don't put that 3Com card into the Model 80!
From the pictures, the cards you have are as follows:
1-3 Game port card
4-5 3Com PCI NIC
6-8 IBM 300/1200 modem card (more below)
9-10 IBM 8514/A Graphics card (more below)
11-12 IBM Audiovation sound card
That particular version of the IBM 300/1200 modem card is a new one on me. I had no idea there was a short version of the card. It's from a different maker as well. The long 300/1200 modem card was made by Racal-Vadic, this short one says it's made by OKI.
The "sandwich card" is an IBM 8514/A graphics adapter. 8514 is a high resolution graphics system (1024x768 ) with either 16 or 256 colors available. The color depth is determined by the amount of video memory on the card. There are some drawbacks...the 8514 graphics adapter is not exactly fast, and its refresh rate is very low (43 Hz vertical, interlaced). This leads to the potential for a lot of flicker, especially on fine lines and some shapes. IBM sold 8514 and 8515 monitors with longer persistence phosphors to alleviate some of the flicker. Newer CRT monitors will almost always sync up to the 8514 card's signal, though flat panel displays usually will not. However, any CRT monitor than the 8514/8515 will likely make the "flicker" worse, due to shorter persistence phosphors.
It's possible that if you have any kind of photosensitivity condition (such as epilepsy) that the 8514 could set it off.
The 8514 adapter is also a one-trick pony. 8514-level graphics are all it does. All other video modes are generated using the system's onboard VGA and passed through the 8514 card to your monitor.