That is very strange, your plate voltage should not be that low
( looking at the SAMMS for your TV, ) point 108 into r156 ,at 260v or near that (unlikely that it's not ) point 90 ( before into L25 ) should be 255v ish, Out of L25 (at 8.8 ohms ) there should be little voltage loss.
-4.9v on g1, normal, 148v g2 , normal, even if there is no signal out of L24, v17a should not be in a full on state, so there must be a loss of voltage between the power point ( r156 or l25 ) or somehow there is a short from plate to 2nd grid ( very weird )