Find out if there is available to you an SNMP node that will answer queries you send it. If so, locate some SNMP utilities (e.g., the ucd - snmp suite) and try the following:
(a) Fetch the entire system group, using something like snmpwalk nodename public system
Also try the above with 1 in place of system
(b) Manually walk through the system group, using multiple SNMP GET-NEXT operations (e.g., using snmpgetnext or equivalent), retrieving one entry at a time.