512Ke to Powerbook: LocalTalk, PhoneNET. You will need a AAUI adaptor for the 5300cs if you want Ethernet on it.
512Ke to eMac (700 or 800MHz model): DE-9 to PhoneNET (preferred) or DE-9 to mini DIN 8 with a PhoneNet adaptor or splitter connected to the iPrint which goes to the eMac
PowerBook to eMac: LocalTalk to PhoneNET, PhoneNet to iPrint, to eMac via Ethernet
PowerBook to 512Ke: already covered
PowerBook to MBP: AAUI to Ethernet, Ethernet to Ethernet (or PCMCIA solution)
512Ke to MBP: Serial terminal or something like that. You could use the eMac as a bridge Mac.
eMac to MBP: Ethernet
10.2.8 is fine, 10.3 is a bit more refined though. I have heard of issues with 10.3 and AppleTalk. You will need classic Appletalk enabled in NetInfo Manager. See the link in my sig. I don't know what your MBP is running but if it is 10.7, you cannot connect your PB to it without something like FTP or terminal stuff. Host NetPresenz on the PB or...eMac as a bridge running 10.2.8/10.3. Again - link in sig.
512Ke to eMac (700 or 800MHz model): DE-9 to PhoneNET (preferred) or DE-9 to mini DIN 8 with a PhoneNet adaptor or splitter connected to the iPrint which goes to the eMac
PowerBook to eMac: LocalTalk to PhoneNET, PhoneNet to iPrint, to eMac via Ethernet
PowerBook to 512Ke: already covered
PowerBook to MBP: AAUI to Ethernet, Ethernet to Ethernet (or PCMCIA solution)
512Ke to MBP: Serial terminal or something like that. You could use the eMac as a bridge Mac.
eMac to MBP: Ethernet
10.2.8 is fine, 10.3 is a bit more refined though. I have heard of issues with 10.3 and AppleTalk. You will need classic Appletalk enabled in NetInfo Manager. See the link in my sig. I don't know what your MBP is running but if it is 10.7, you cannot connect your PB to it without something like FTP or terminal stuff. Host NetPresenz on the PB or...eMac as a bridge running 10.2.8/10.3. Again - link in sig.