Bish:
From the looks of those photo's, the pads seem to be fitted into a hole in each track link and therefore shows on both the inside and out. Very unusual design. I am not sure how those pads would be removed and replaced. I can only imagine they just replace the whole track rather than the pads.
The design of this style of track hasn't really changed much in 40+ years. The design (similar, just bigger with a molded on chevron pattern) was used on the M1/M1A1 original style track and still used on the M88A1/A2 track today. No track pads, the entire block is rubber molded around metal track pins.
The replaceable track pads always come around later as a money saving measure. It is cheaper to have the crews replace individual pads as needed than to replace entire track blocks.