my WIF paper wallet from around 2013 was damaged due to rats chowing thru area where it was stored, it held majority of my bitcoin holdings from years of solo-mining and after consulting various local experts it appears to require significant computing resources to have it recovered

Now I am giving bitcointalk a try to see if someone here could shed some light on actual algorithmic complexity so to have an idea when would it be technologically / economically feasable to have it recovered

I am using the following example to give you guys an idea on scope of damage:

Let

5KFE3ScWZMf4TdAuVNYKDU7UtTBmHf9M           LHs1AkbD

be the damaged key, and:

suppose the DHiTxZ8xUrg portion was damaged (rat chewed it away..), where the full key *if* successfully recovered in this example should be

5KFE3ScWZMf4TdAuVNYKDU7UtTBmHf9MDHiTxZ8xUrgLHs1AkbD

with 11 char missing now the complexity for recovery is somewhere around 2498664400016553792, or 2.5 x 10^19!

The problem is further complicated by the fact that WIF algorithmically requires 2 rounds of sha256 calculation, which is very slow to checksum in my poor attempt to "guess at" even with access to computing resources with large number of cores (like AWS).

Not sure if someone can offer some formal asymptotic analysis on the aforesaid situation.  Maybe I am not approaching this problem correctly, but I guess someone might have a better idea in similar situations

and of course Happy new year all! 恭喜發財!