Rik's page here says SCUS0488 is LCD Controller: Hughes SCUS0488 (Custom multiplexed display driver circuit) U. S. Patent # 4,359,222. http://www.handheldmuseum.com/MB/uVUS.htm
pinouts: http://www.atarihq.com/danb/Microvision.shtml

This book also suggests "Hughes" as manufacturer for the other HLCD part numbers you name: https://books.google.com/books?id=qkqyJyEJxGAC&pg=PA80&lpg=PA80

It appears that Ingo has a 4-page datasheet on these HLCD chips (I expect it's 4 pages shared on all these), I can request it if you want:

These websites have some simple specs on HLCD0541P:

Here's another device with an HLCD0541P: http://www.handheldmuseum.com/forum/viewtopic.php?t=701