Y1 is a ceramic resonator from Murata Electronics, part number CSTCE16M0V53-R0. This is a widely-used 16MHz ceramic resonator with built-in 15pF capacitors, commonly used in microcontroller clock circuitry.

As a specific replacement, you can look for a similar 16MHz ceramic resonator with similar built-in capacitor values, such as:

Note: When selecting alternative parts, please verify their electrical and physical compatibility to ensure they can be properly interfitted within your existing circuit design and layout in Flux. It's always recommended that you thoroughly review the datasheets as part parameters can vary even with equivalent replacements.

The U2 component in your project is a voltage regulator with the part number "NCP1117ST50T3G", manufactured by onsemi. This is a 5V, 1A Low Dropout Voltage Regulator (LDO) in a SOT-223 package.

A possible replacement could be the "LM1117IMPX-5.0/NOPB" from Texas Instruments. Here are its main features:

Please make sure to validate this recommendation with your specific requirements and constraints (footprint, cost, availability), as there could be other factors influencing the choice of a replacement part.

Is there a specific reason for replacing NCP1117ST50T3G, like unavailability or cost? If so, I could provide more tailored recommendations.