I Googled the cot top, and I pretty much only found a Cariboo brand one that sells for $169-$300! I then checked eBay and saw an item from the UK, but its shipping cost is prohibitive:
http://www.ebay.com/itm/COT-TOP-CHANGING-UNIT-NURSERY-PRINTS-MAT-2-1-/180614202441Does that look like what you used? There are also tunnels for toddlers like this:
http://www.amazon.com/Pacific-Play-Tents-See-Tunnel/dp/B0007YDC0E/But they're not the right material, and the wire supports might make it harder for an infant to crawl, and I don't think the tunnel part would be useful for feet-pushing-off.
Probably just a foam mat is the best, cost-effective, ready-made option, then...
Hi,
Thanks
It was me who mentioned the "cot-top changer" It is a kind of hard mat that fits across the top of a crib for changing the baby. The reason I used it was because it has foam and then plastic stuff, like Doman suggests, although it isn't tunnel shaped. Maybe you could buy one and put it on the floor. Can't remember how much they are, sorry...