diff --git a/rcsfile.py b/rcsfile.py
index 692a999..52dbe2f 100644
--- a/rcsfile.py
+++ b/rcsfile.py
@@ -1,11 +1,11 @@
 #!python
 # RCSFile class and supporting functions / parsers
 # Copyright (C) 2011 Ryan Kavanagh <rak@debian.org>
-# 
+#
 # Permission to use, copy, modify, and/or distribute this software for any
 # purpose with or without fee is hereby granted, provided that the above
 # copyright notice and this permission notice appear in all copies.
-# 
+#
 # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 # REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 # FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
@@ -129,25 +129,25 @@ class RCSFile:
 
     """
 
-    def __init__(self, lines=None, file=None):
+    def __init__(self, lines=None, rcsfile=None):
         """ Initialise the object with the lines of an RCS file. """
-        if lines and not file:
+        if lines and not rcsfile:
             parsed = RCStext.parseString(''.join(lines))
-            self._filename = '?'
-        elif file and not lines:
-            parsed = RCStext.parseFile(file)
-            if type(file) is str:
-                self._filename = file
-            elif type(file) is file:
-                self._filename = file
+            self._filename = ('?', None)
+        elif rcsfile and not lines:
+            parsed = RCStext.parseFile(rcsfile)
+            if isinstance(rcsfile, basestring):
+                self._filename = (rcsfile, None)
+            elif isinstance(rcsfile, file):
+                self._filename = (rcsfile.filename, rcsfile)
             else:
-                self._filename = '?'
+                self._filename = ('?', None)
         else:
             raise ValueError('Either lines or file must be provided')
-        # self._lines will contain all lines, newline characters removed
-        self._lines = []
+        # self._parsed will contain the full parsed result
+        self._parsed = parsed
         # self._admin will contain the admin block's values
-        self._admin = parsed.admin
+        self._admin = self._parsed.admin
         # self._symbols will contain tags / symbols
         self._symbols = dict(map(lambda s: s.split(':'),
                                  self._admin.symbols))
@@ -158,16 +158,57 @@ def __init__(self, lines=None, file=None):
         self._deltatexts = dict((deltatext.deltanum, deltatext)
                             for deltatext in parsed.deltatexts)
 
+    @property
+    def deltas(self):
+        """
+        A read-only property exposing the deltas.
+        Note: this is not strictly read-only. Only the underlying class variable
+              cannot be set.
+        """
+        return self._deltas
+
+    @property
+    def deltatexts(self):
+        """
+        A read-only property exposing the deltatexts.
+        Note: this is not strictly read-only. Only the underlying class variable
+              cannot be set.
+        """
+        return self._deltatexts
+
+    @property
+    def filename(self):
+        """ A read-only property exposing the file name in string form. """
+        return self._filename[0]
+
+    @property
+    def parsed(self):
+        """
+        A read-only property exposing the whole parsed results.
+        Note: this is not strictly read-only. Only the underlying class variable
+              cannot be set.
+        """
+        return self._parsed
+
+    @property
+    def symbols(self):
+        """
+        A read-only property exposing the symbols (all of them!).
+        Note: this is not strictly read-only. Only the underlying class variable
+              cannot be set.
+        """
+        return self._symbols
+
     def get_deltanums(self):
         """ Returns a list of all delta numbers. """
-        return [d.deltanum for d in self._deltas]
+        return [d for d in self._deltas.keys()]
 
     def get_delta(self, deltanum):
         """ Return metadata about delta delta. """
         try:
             return self._deltas[deltanum]
         except KeyError:
-            raise ValueError('Delta %s does not exist.' % delta)
+            raise ValueError('Delta %s does not exist.' % deltanum)
 
     def get_deltatext(self, deltanum):
         """ Return the deltatext for delta deltanum. """
@@ -205,7 +246,7 @@ def get_ancestor_tuples(self, deltanum):
         ancestors = []
         for i, next in enumerate(nexts):
             if next[0] == deltanum:
-                # Probably more effecient that using 'nexts.remove'
+                # Probably more effecient than using 'nexts.remove'
                 # since we don't have to search the whole list
                 ancestors.append(nexts.pop(i))
                 break
@@ -465,7 +506,7 @@ def grep(self, pattern, format="rlL", wraplines=False):
                     elif attr == 't':
                         formatted_match.append(self.get_tags(match[0]))
                     elif attr == 'f':
-                        formatted_match.append(self._filename)
+                        formatted_match.append(self._filename[0])
                     elif attr == 'm':
                         formatted_match.append(self.get_message(match[0]))
                     else: