Airfix Green Class 31 - replacement headcode decals?

[Metr0Land]

I've got a couple of green Airfix Class 31's which still perform well and respond ok to some T-Cut and weathering etc (I know some people prefer the Lima body but this is what I have).

 

Unfortunately they both have those 'C' headcodes and I'd like to replace these.  I did think about trying to produce something at home but the home printer is a bit poorly at the mo' so that's not an option.

 

Amongst the various Headcode panels on offer (eg Precision labels) no-one seems to do anything specific for the Airfix 31.

 

As all these headcode panels on 4mm models seem to be ever so slightly dis-similar I was wondering if anyone had had any success using something meant for another type of loco?  Ideally am looking for a pack that contains 2Ann and 2Bnn though I can be persuaded to look at anything else that's a good fit.