Renee - generally as one gets older it is considered safer (re blood clots, stroke etc) to change to transdermal HRT rather than tablets though this is generally advised over 60 unless you have other risk factors (eg obesity, high BP, smoking, sedentary lifestyle etc). If taking tibolone once every three days was working for you then that's great! Yes it is a lower dose than the standard but so what - it is going to have less risk attached to it if at a lower dose.
That being said - why not try the patch and utrogestan? However some find taking utrogestan continuously gives rise to unwelcome side effects - I don't take it continuously for this reason.
Re Testosterone - blood tests are not reliable in determining the need for this - a better indication would be your libido and specifically, your response - if lacking or has declined considerably then this would suggest T might be helpful. If this has declined since stopping Tibolone then this is another argument to go back on it as Tibolone is a special type of HRT and contains a hormone that acts like testosterone, and some find it good for libido/response.
Hurdity x