These issues were seen on Junos 22.4R3.23-EVO: 

1) "part-no" leaf shows up on the PTX10004 but not on the PTX10008

2) "hardware-version" leaf shows up on the PTX10004 but not on the PTX10008

The path subscribed to is: /components/component 

"ucgDeviceName": "LR1-WASKDCFN-TPC3-TPC01",
"ucgJsonData": {
"components": {
"component": {
"CHASSIS0": {
"name": "CHASSIS0",
"state": {
"allocated-power": 0,
"base-mac-address": "a4:e1:1a:68:87:1c",
"base-num-mac-addresses": 4095,
"description": "JNP10008 [PTX10008]",
"empty": false,
"id": "EX850",
"location": "CHASSIS0",
"mfg-date": "0000-00-00",
"name": "CHASSIS0",
"oper-status": "ACTIVE",
"parent": "CHASSIS0",
"removable": false,
"serial-no": "EX850",
"software-version": "22.4R3.23-EVO",
"type": "CHASSIS",
"used-power": 0
}
}…
"ucgDeviceName": "DLLSTX64-TPC3-AC",
"ucgJsonData": {
"components": {
"component": {
"CHASSIS0": {
"name": "CHASSIS0",
"state": {
"allocated-power": 0,
"base-mac-address": "48:73:10:01:1f:fe",
"base-num-mac-addresses": 4096,
"description": "JNP10004 [PTX10004]",
"empty": false,
"hardware-version": "",
"id": "FK986",
"location": "CHASSIS0",
"mfg-date": "0000-00-00",
"name": "CHASSIS0",
"oper-status": "ACTIVE",
"parent": "CHASSIS0",
"part-no": "",
"removable": false,
"serial-no": "FK986",
"software-version": "22.4R3.23-EVO",
"type": "CHASSIS",
"used-power": 0
}
}...

The path subscribed to is: /components/component
In customer's PTX10004, the result is below:
"ucgDeviceName": "ABC_ROUTER",
"ucgJsonData": {
"components": {
"component": {
"CHASSIS0": {
"name": "CHASSIS0",   <<<<<<<<<<<<<<<<<
"state": {
"allocated-power": 0,
"base-mac-address": "48:73:10:01:1f:fe",
"base-num-mac-addresses": 4096,
"description": "JNP10004 [PTX10004]",
"empty": false,
"hardware-version": "",     <<<<<<<<<<<<<<<<<<<
"id": "FK986",
"location": "CHASSIS0",
"mfg-date": "0000-00-00",
"name": "CHASSIS0",
"oper-status": "ACTIVE",
"parent": "CHASSIS0",     
"part-no": "",       <<<<<<<<<<<<<<<<<<<<
"removable": false,
"serial-no": "FK986",
"software-version": "22.4R3.23-EVO",
"type": "CHASSIS",
"used-power": 0
}
But on a PTX10008, the port-no and hardware-version are missing from the result:
"ucgDeviceName": "DEF_ROUTER",
"ucgJsonData": {
"components": {
"component": {
"CHASSIS0": {
"name": "CHASSIS0",
"state": {
"allocated-power": 0,
"base-mac-address": "a4:e1:1a:68:87:1c",
"base-num-mac-addresses": 4095,
"description": "JNP10008 [PTX10008]",
"empty": false,
"id": "EX850",
"location": "CHASSIS0",
"mfg-date": "0000-00-00",
"name": "CHASSIS0",
"oper-status": "ACTIVE",
"parent": "CHASSIS0",
"removable": false,
"serial-no": "EX850",
"software-version": "22.4R3.23-EVO",
"type": "CHASSIS",
"used-power": 0
}

These issues are resolved in 22.4R3.S3-EVO and later.