Hi sajurcaju,
Welcome to the Mattress Forum!. 
There really is no one who can tell you what they have will be an exact match of what you purchased five years ago. Foam technologies advance and formulations change. The density isn’t a softness indicator (that is IFD/ILD), and although all memory foam tends to be plush (in the range of 10-18 IFD/ILD), there are certainly large variations in recovery time, rebound, resilience, breathability, cell structure, gel and polymer additives, etc. The recent trend has been toward memory foams that recover faster and are more breathable than their previous versions.
My best suggestion would be to contact the memory foam vendors in the component post here and speak with them and let them know that you have an “old school” (no gels or phase change materials) piece of 5.3 lb. memory foam that you are attempting to replicate. Many of them will even be able to send you out samples which you may compare to your current foam piece. Realize that your topper is five years old so it certainly has changed in comfort over that time, but at least this will give you a better starting point.
I’ll be interested to know if you find what you’re looking for from these vendors.
Phoenix