SP Designs offers such a kit conversion, and it is mentioned in the Wikipedia T-55 tank description. But have any military forces actually converted any of their vehicles that way, or intend to?

After Omsk 2007 expo, there were some negotiations with reps. from some African states, but it is not known, at least to me, if contracts were ever signed. IMHO, T-55M5 doesn't looks potent enough once Omsk bureau showed more advanced upgrade in form of M6 version.

T-55M5 is still a one-off show vehicle...no orders for it that I am aware of.

It is a very good upgrade for the price...most of the M6 upgrades go inside and are quite expensive...the M5 version is meant to be the more economical version. As i understand it, it is aimed at countries that do not need a top line MBT with all the associated FCS, but who need to be able to withstand the hit of a fairly modern ATGM, and all on a budget. This is supposed to fit the bill.

It is also supposed to be a wartime expedient to upgrade stored T-55's in Russia. This upgrade offers the best protection with the least amount of "conversion". Maybe it would be a waste of resources, but the idea is then the venerable T-55 could compete with all but the most modern MBT's and would be quite a handfull for any unit without MBT's.