Whoa!, avoid measuring PL38's anode and the EY51 dirrectly !
You don't mention that your meter has blown up so I think it is now safe to assume that the frame timebase isn't running and this is cook the PL38, LOP, etc since it needs the timebase running in order to generate a negative bias on it's grid 1.
PL38 connections can be found here :-
http://www.r-type.org/exhib/aaa0497.htm
If it were me, I'd disconnect the PL38's top cap AND disconnect it's screen (important) whislt investigating the problem to avoid damage. Even with these pins disconnected, you should still get a negative voltage developed on it's grid if the timebase is running.
So, on the assumption it 'aint running, and that you have already mentioned you've done a cap replacement then :-
1) Check the primary and secondary of the blocking transformer for O/C.
2) Check DC resistance between V14 osc valve's grid and 0v, and check the grid resistors.
3) Double check you have correctly connected the replacement caps and ensure connections are good. Please don't take offence with this suggestion, we've probably all been there and got the T-shirt
4) Check picture width control - if the slider contact is poor / open then again no frame osc !
5) Well, caps checked, transformer checked, resistors checked so that can only leave checking the oscillator valve by replacement.
If it turns out to have been the oscillator at fault then I'd recommend changing the PL38's cathode resistor anyway as it will have taken a pounding.
TTFN,
Jon