Hello,
The first picture seems to show a Macintosh IIvx without an optional CD-ROM drive (the original was a 2X caddy model). With the proper hardware, it should be possible to install a SCSI CD-ROM drive in the empty space.
See also:
http://support.apple.com/kb/SP202
http://developer.apple.com/legacy/library/documentation/Hardware/Developer_Notes /Macintosh_CPUs-68K_Desktop/Mac_IIvx.pdf
http://www.everymac.com/systems/apple/mac_ii/specs/mac_iivx.html
http://lowendmac.com/1992/mac-iivx/
A IIvx manual does not appear to be available for download. However, the Performa 600 is basically the same computer with different software:
http://manuals.info.apple.com/en_US/0307230AATVVDOUG.pdf
Have you tried to eject the floppy using one of the methods on page 84 in the aforementioned Performa 600 series manual? Otherwise, you may have to (carefully) disassemble the floppy drive. It cannot be ruled out that the shutter has damaged the heads, but with luck it may be possible to remove the diskette with the drive intact.
System software 7.5.3 (British and US versions) can be found here:
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -British/Macintosh/System/Full_Installs/System_7.5_Version_7.5.3/
http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/System/Older_System/System_7.5_Version_7.5.3/
The 7.5.3 downloads do not contain normal system disks (see the text files for details). It would be good if the floppy drive can be made to work, though. Plain transfers of the individual files are possible on 1.44 MB floppy disks. Other ways include a null-modem transfer (if the IIvx is operational, with a suitable system already on the hard disk) or a transfer on a CD-ROM disc (which of course would require a CD-ROM drive with correct CD-ROM driver software).
If you see an error message while attempting to access the Apple download servers, try to reload the page (if necessary, repeatedly).
Jan