[SecTa]

The line

<hr size="1" style="color:$stylevar[tborder_bgcolor]" />

is not that good, cause it's used for "Last edited" separation, so, it's better to leave the original one. Also, when applying this hack, "last edited' info is shown ABOVE the signature, which is not good. And there's signature hooks appear to be misplaced.
Here's my alternative to this hack, with needed fixes:

In postbit_legacy, find:

	<td class="alt2" width="175" style="border: $stylevar[cellspacing]px solid $stylevar[tborder_bgcolor]; border-top: 0px; border-bottom: 0px">

Change to:

	<td class="alt2" width="175" rowspan="2" style="border: $stylevar[cellspacing]px solid $stylevar[tborder_bgcolor]; border-top: 0px; border-bottom: 0px">

Then find:

		$template_hook[postbit_signature_start]
		
		<if condition="$post['signature']">
		<!-- sig -->
			<div>
				__________________<br />
				$post[signature]
			</div>
		<!-- / sig -->
		</if>
		
		$template_hook[postbit_signature_end]
		
		<if condition="$show['postedited']">
		<!-- edit note -->
			<div class="smallfont">			<hr size="1" style="color:$stylevar[tborder_bgcolor]" />
				<em>
				<phrase 1="$post[edit_username]" 2="$post[edit_date]" 3="$post[edit_time]">$vbphrase[last_edited_by_x_on_y_at_z]</phrase>.
				<if condition="$post['edit_reason']">$vbphrase[reason]: $post[edit_reason]</if>
				</em>
			</div>
		<!-- / edit note -->
		</if>
	
	</td>
</tr>

Replace With:

	</td>
</tr>
<tr>
<td class="alt1" valign="bottom" style="border-right: $stylevar[cellspacing]px solid $stylevar[tborder_bgcolor]">
		$template_hook[postbit_signature_start]
		<if condition="$post['signature']">
		<!-- sig -->
			<div valign="bottom">
			    __________________<br />
			    $post[signature]
			</div>
		<!-- / sig -->
		</if>
		$template_hook[postbit_signature_end]
		<if condition="$show['postedited']">
		<!-- edit note -->
			<div class="smallfont">			<hr size="1" style="color:$stylevar[tborder_bgcolor]" />
				<em>
				<phrase 1="$post[edit_username]" 2="$post[edit_date]" 3="$post[edit_time]">$vbphrase[last_edited_by_x_on_y_at_z]</phrase>.
				<if condition="$post['edit_reason']">$vbphrase[reason]: $post[edit_reason]</if>
				</em>
			</div>
		<!-- / edit note -->
		</if>
		</td>
</tr>

Works with vB 3.6.7
Sledgstone, could you please update your first post?