So, just FYI, I've lost patience with trying to verify this myself. The only way I have to run Classic OS currently is via emulation, and attempts to set this in BasiliskII were completely stymied by some bizarre dependency the Desktop Printer LPR support seems to have on *Appletalk*. I get through the setup fine (IE, it "sees" the print server, blaw blaw), but when trying to actually spool something it gives me this error about Appletalk not being enabled for that network. Eh, what? YOU'RE PRINTING VIA TCP/IP, STUPID! Maybe it'd work better in SheepShaver, the networking is a little better there, but... I've wasted too much time already.
I swear I got this to work in the past, but it was on a "real" Mac... and possibly complicating the matter is I did happen to have a Netatalk server acting as a router so Appletalk was also "present" on the LAN. (Which is something I'm lacking now.) Apparently this software has some idiotic and broken dependencies in it. So... forget LPD sharing? I'm sorry I ever mentioned it.
At this point if you really want to print directly from your old Macs I'd suggest two courses of action:
1: A Linux box with NetaTalk hosting the printer would make all your problems go away. The problem is you need to get a Linux box, set it up (and there's no GUI for Netatalk... it's not "hard", but it seems to be a formidable wall for people not used to the alternative) and run it as a server whenever you want to print.
2. See what the cheapest network-enabled Postscript laser printer you can buy is. "Cheap" home network printers don't offer Appletalk anymore, but office models do. (The Brother HL6050DN does, for instance.) If it's worth, oh, $350 or so, to print from your old system that's your "new" option. Or of course you could always find a used one. The old postscript-equipped HP 4-series network models are well regarded, if getting extremely long in the tooth. One issue with "office caliber" printers I've encountered is if you live in an older house with cruddy wiring you can end up dimming the lights every time one of the monsters fires up.
If you were running XP there *are* illicit instructions for lifting the AppleTalk DLLs from a Windows 2000 Server installation and inserting them into the right places to enable Appletalk on XP, but I'm sure that wouldn't work for Vista. (And I wouldn't trust it on XP either, but that's just me.) Sorry about the faceplant fail.