Hi Mark:
The eth_to_serial demo is in classic MQX 4.2 RTCS stack, but not in SDK.

Regarding your web page server issue, we have a httpsrv demo, it demonstrates an HTTPServer on the lwIP TCP/IP stack , but not implement displaying/setting pin informaiton
SDK_2.3.0_FRDM-K64F\boards\frdmk64f\demo_apps\lwip\lwip_httpsrv

Regards
Daniel