Philips QL driver

This is the inside circuit board of a Philips QL 85W HF generator from 1996. I hadn’t opened this before as a tamper ‘No serviceable parts’ label required to be broken. Obviously not aimed at me. I actually wanted to look at it because I saw a picture of proto-type unit and it has a 555 timer IC on the board. Everyone know knows nothing commercial ever uses a 555 timer, so I had to open up this unit and check. It is a little more complex that I imagined. Notice the spit on the p.c.b. This is for a screening can to slide over this section as it is the RF driver section of the unit. There are two driver transistors spring loaded to press against the shielding can for heat dissipation. There is also a tuneable inductor in the small metal can. Notice this area has been quite hot going by the look of the p.c.b. surface. The board has quite a lot of passive components on the underside.
No signs of a 555 IC but there is an 8-pin SMT on the underside. I can’t trace the part number but think it may be a comparator or op-amp. I’ll give it the benefit of the doubt its not a 555 in disguise.
On the underside there is a couple of jumper pads for setting 120V and 55W but the circuit etch doesn’t connect them anywhere as if an option not implemented.