Another Traynor Question

I have in my sights a '69 Traynor Bass Master Mark II. He thinks it's a YBA-1, yet swears it has 90 watts, which I think the YBA-1A touts. I've looked at most of the Traynor threads, most of them at least 2 years old. The back does not have the YBA-1A printed next to the speaker outputs, just LR 21877. New EL34 tubes, original pre-tubes. The circut has been taken to original specs. I will need the higher watts, as I plan to play out with this puppy. Maybe a 2x12 cab, or a 115. The question is, what will positively identify the model of this amp. Thanks.