Rlacement of MOSfets alone can't not solve the case.
However there is reasonable improvement,. Interestingly, there is a dip in gain at 21.2MHz and recovered at 28 MHz. Twe need to analyse this behaviour. I wonder what would happen if we can tweak C261 and C262 by lowering their values , say 68nF instead of 100nF !! ??
If R97 and R98 could be increased to say 100 ohms, the gate loading would reduce, I agree that, we need to ensure thast amplifier would not become unstable.