diff --git a/Makefile b/Makefile
index f8f052d..f16db58 100755
--- a/Makefile
+++ b/Makefile
@@ -55,7 +55,7 @@ build-python:
 	@find ./Python.framework -name '*.pyc' -delete
 
 sign: remove-xattrs
-	@sudo ./sign_python_framework.py -v -S "${DEV_APP_CERT}"
+	@sudo ./sign_python_framework.py -v -S "${DEV_APP_CERT}" -L ${WORK_D}/usr/local/sal/Python.framework
 
 remove-xattrs:
 	@sudo xattr -rd com.dropbox.attributes ${WORK_D}
diff --git a/payload/usr/local/sal/checkin_modules/machine_checkin.py b/payload/usr/local/sal/checkin_modules/machine_checkin.py
index 27634b7..877815d 100755
--- a/payload/usr/local/sal/checkin_modules/machine_checkin.py
+++ b/payload/usr/local/sal/checkin_modules/machine_checkin.py
@@ -42,16 +42,20 @@ def process_system_profile():
         # We can't continue if system_profiler dies.
         return machine_results
 
-    machine_results["serial"] = system_profile["SPHardwareDataType"][0]["serial_number"]
-    os_version = system_profile["SPSoftwareDataType"][0]["os_version"].split()[1]
+    machine_results["serial"] = system_profile["SPHardwareDataType"][0].get(
+        "serial_number"
+    )
+    os_version = system_profile["SPSoftwareDataType"][0].get("os_version").split()[1]
     if os_version == "X":
-        os_version = system_profile["SPSoftwareDataType"][0]["os_version"].split()[2]
+        os_version = (
+            system_profile["SPSoftwareDataType"][0].get("os_version").split()[2]
+        )
     machine_results["operating_system"] = os_version
-    machine_results["machine_model"] = system_profile["SPHardwareDataType"][0][
+    machine_results["machine_model"] = system_profile["SPHardwareDataType"][0].get(
         "machine_model"
-    ]
+    )
 
-    udid = system_profile["SPHardwareDataType"][0]["provisioning_UDID"]
+    udid = system_profile["SPHardwareDataType"][0].get("provisioning_UDID")
     friendly_model = get_friendly_model(serial=machine_results["serial"], udid=udid)
     if friendly_model:
         machine_results["machine_model_friendly"] = friendly_model
@@ -63,12 +67,12 @@ def process_system_profile():
         machine_results["cpu_type"] = system_profile["SPHardwareDataType"][0].get(
             "cpu_type", ""
         )
-    machine_results["cpu_speed"] = system_profile["SPHardwareDataType"][0][
-        "current_processor_speed"
-    ]
-    machine_results["memory"] = system_profile["SPHardwareDataType"][0][
-        "physical_memory"
-    ]
+    machine_results["cpu_speed"] = system_profile["SPHardwareDataType"][0].get(
+        "current_processor_speed", ""
+    )
+    machine_results["memory"] = system_profile["SPHardwareDataType"][0].get(
+        "physical_memory", ""
+    )
     machine_results["memory_kb"] = process_memory(machine_results["memory"])
 
     for device in system_profile["SPStorageDataType"]:
@@ -116,7 +120,13 @@ def get_friendly_model(serial, udid):
         try:
             data = plistlib.loads(out)
             if len(data) != 0:
-                return data[0].get("product-name").decode("utf-8")
+                return (
+                    data[0]
+                    .get("product-name")
+                    .encode("ascii", "ignore")
+                    .decode()
+                    .strip()
+                )
         except:
             pass
 
diff --git a/sal_python_pkg/sal/version.py b/sal_python_pkg/sal/version.py
index 0fd7811..aef46ac 100644
--- a/sal_python_pkg/sal/version.py
+++ b/sal_python_pkg/sal/version.py
@@ -1 +1 @@
-__version__ = "4.2.0"
+__version__ = "4.2.1"
diff --git a/sign_python_framework.py b/sign_python_framework.py
index 7725372..4f70c27 100755
--- a/sign_python_framework.py
+++ b/sign_python_framework.py
@@ -37,12 +37,6 @@
 
 PYTHON_VERSION = "3.9.7"
 SHORT_PYTHON_VERSION = "3.9"
-TOOLS_DIR = os.path.dirname(os.path.realpath(__file__))
-
-
-PY_FWK = os.path.join(TOOLS_DIR, "Python.Framework")
-PY_CUR = os.path.join(PY_FWK, "Versions/Current")
-
 
 PRODUCTSIGN = "/usr/bin/productsign"
 CODESIGN = "/usr/bin/codesign"
@@ -136,11 +130,20 @@ def main():
         "-S",
         "--sign-binaries",
         action="store",
+        dest="sign_binaries",
         default=None,
         help="A Developer ID Application certificate from keychain. "
         "Provide the certificate's Common Name. e.g.: "
         "'Developer ID Application  Munki (U8PN57A5N2)'",
     ),
+    p.add_argument(
+        "-L",
+        "--location",
+        action="store",
+        dest="location",
+        default=None,
+        help="Path to python framework to sign.",
+    ),
     p.add_argument("-v", "--verbose", action="store_true", help="Be more verbose"),
 
     args = p.parse_args()
@@ -159,7 +162,11 @@ def main():
     global verbose
     verbose = args.verbose
 
-    root_dir = os.path.join(TOOLS_DIR, "Python.framework")
+    if not args.location:
+        print("Path to Python.framework must be provided.")
+        sys.exit(1)
+    root_dir = args.location
+    PY_CUR = os.path.join(root_dir, "Versions/Current")
     # Set root:admin throughout payload
     for root, dirs, files in os.walk(root_dir):
         for dir_ in dirs:
@@ -227,7 +234,7 @@ def main():
             entitlements=ent_file,
         )
     # Finally sign python framework
-    py_fwkpath = os.path.join(root_dir, PY_FWK)
+    py_fwkpath = os.path.join(root_dir, root_dir)
     if verbose:
         print(f"Signing {py_fwkpath}...")
     sign_binary(args.sign_binaries, py_fwkpath, deep=True, force=True)