VECTOR: Transistor cross references

Hey all

I'm looking for a cross reference for the MPSU07 and MPSU57 on my Star Wars
deflection board.  The whole machine works just fine now (I've had it
running using a borrowed deflection PCB!) so I really want to sort this out
asap!  I see that I can use either SK3199/SK3200 or NTE188/NTE189 or
BD529/BD530 but *none* of these parts are obtainable easily in the UK.  I
did however stumble across a cross reference which suggests using
BD237/BD238 which are widely available everywhere...  But I'm not entirely
sure about the specs:

http://documents.rs-components.com/rs-bin/RightSite.dll/getcontent/data.pdf?
DMW_FORMAT=pdf&DMW_OBJECTID=0900766b80224c77&DMW_DOCBASE=techlib

However I've read docs which suggest replacing these with a higher powered
NTE49/NTE50 though?  Not that I can find these either ;o)  But then again,
I've not even bothered looking for cross references yet!  Would it be better
to be searching for these instead?

Can anyone please offer any advice?  TIA :o)

Paul