No. 7.5.x was unique in the ability to run either MacTCP or OpenTransport. The switcher application is unique to 7.5 and will not work with any earlier version or any later version of System 7.
7.6 and up included OT in the software and does not use MacTCP. I've never tried to "force" MacTCP onto 7.6, though.
OP, the link in my signature should explain most elements relevant to you. For 7.5.3 up to 8.1, use OT 1.3. It all depends on what you'd like to do though.
The only time I use DHCP is for Macs that access the internet. All others benefit greatly from using manually assigned IP addy's. MacTCP does not support DHCP, although it does support some cryptic "Server" setting, but you don't need it to go online.
For writing disk images, the Working with Disk Images section should be helpful. Short story: Windows -- use Rawrite and NDIF disk images. OS X - $ dd for DC 4.2 or NDIF images. DU or DC can work with NDIF images. Only a machine with a built-in FDD or compatible external can work with 800Ks.