The replacement issue is not too difficult to resolve however I am looking for a TIP36 like transistor with a lower beta than tip36.
In fact I am presently using TIP36 however I am looking for similarly specced transistor with a beta of 15 to 20 at collector current of 10 amps.
BD250 seems like a suitable candidate unfortunately it is obsolete.
EDIT: obsolete according to some suppliers , element14 claims 600 odd pieces world wide.
Element14 offers a Multicomp device which is different to some older sources... back to square one.