Wooden block under bridge on '60s ES-125?

What's the deal with this? I see some '60s ES-125s with the wooden (rosewood?) base under the bridge, and others where it just looks like a normal ABR-1 style bridge, with no wooden base block, that screws directly into the guitar?

Was there a year where the ES-125 transitioned away from the wooden base block bridge?

Here are some pictures just to demonstrate:

Wooden block under bridge - a 1966 model:

http://cgi.ebay.com/1966-GIBSON-USA...yZ118985QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

No wooden block - ABR-1 goes directly into body - a 1967 model:

http://cgi.ebay.com/1967-GIBSON-ES-...ryZ38085QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

So did I just answer my own question? Was the change in 1967?

I believe the way the neck is mounted is very different on an ES-125 thinline compared to an ES-125 deep body. On the first type the fingerboard is almost glued down flat on the top as per ES-330 whereas on an ES-125 with a deep body it's much more like an ES-175 with the neck elevated at the heel and angled differently leaving much more space between the top and the strings leaving room for a wooden "bridge base" (which it's called - not a wooden block). On this model the bridge is kept in position by the the string downforce exclusively. On the thinline the string post are screwed into the top. So the type of bridge used is not a matter of when but which type of ES-125 we are talking about (both have ABR1's - but attached differently).