Just because the specific version of the device is not listed, there may be a parser already for catalyst switches in general or cisco switches that already parses the format of your specific devices.
Probably best to enable logging, turn on the cisco switch parser and see what parses and what does not then determine what your next steps are from there. Some may need custom parsing, some may extract data from the parser tokens capability in 11.2.
Eric
Due it is still arriving by syslog you could identify on which event IDs you are interested and then create a Parser using Log Parser Tool:
https://community.rsa.com/community/products/netwitness/parser-network/event-sources
does this help?