Our bungalow was built in the 1950's, and has this flooring throughout. I had to remove some for reasons that are not relevant, but found that if I cut and laid a 1/2 inch thick piece of marine ply to the size of the blocks ( mine were 10.5"x 2.75" x 3" thick ) on top of the first block, then gave it a good smack or two with a lump hammer it broke the joint between the concrete floor and the hard bitumen that was laid originally to fix it. There is no tongue & groove - just straight sided blocks - I am not saying yours are the same, but the same principle may apply. Then screw a small screw at the end of the block - 1" in. Place the ply onto the next block to protect its face, and use a claw hammer to GENTLY lift/rock the block, and it will eventually lift, do the same for the other end, and if you had my luck, it will eventually lift out. From then on, you can remove as many as you require. To re-lay, I just scraped the concrete floor with and old bolster, cleaned up the base of the blocks with a chisel, use a piece of sandpaper to make some fine sawdust, and relaid blocks using "No Nails" - worked a treat. Remove lifting screws and fill holes with wood filler ( neutral ) mixed with the sawdust you had made. Depending on the colour of the wood, you can then either stain or brown shoe polish the filler, then a good coat of bees wax. Sorry this goes on a bit - must be my age !! - This may help or may not - good luck,
Kind Regards,
boaz