Firstly my thanks to everyone (so far) who have responded and this is indeed turning out to be a most frustrating exercise.
Printer: HP Laserjet 5
Printer ethernet interface card: Emulex (NetJet) type ER2010293-05
A previous self test via printer's self test/configuration, provided the following info against the printer interface card:
MAC address: 00 00 C9 07 69 2A - note, the colons omitted to fool the filter - otherwise end up as **:**: **: **: **: **
Subnet mask: 255.255.252.0
Default remote printer name: NJA07692A_01
Note, I have no way of changing the IP addresses above as the printer menu map does not have options for ethernet.
Have tried the DHCP option entering the above mac address and assigned an Ip address of 192.168.0.2 which (looks like) to have been accepted as a reserved address, rebooted the hub and the printer with lights showing at the hub and printer interface card.
Bearing in mind that I'm using Linux Mint 19.3 utilising both the inbuilt printer setup function and also the HPLIP (HP Linux Imaging and Printing) software - neither of which can locate the printer.
I'm at a loss as to what may be the problem, sigh ....!
look forward to constructive comments