GBP40 is an OK-but-not-great price but again, that enlarger looks more over-complicated than I would be comfortable with. It has a lot of extraneous electronics (filter-control box and timer) and cables and things (THREE bulbs!) that can fail. In working condition it's probably really neat to use but maintenance and reliability is now the real problem because no one makes these things any more, not for a price you want to pay.

What you want is a lightbulb in a metal box with bellows and a lens on the front, and you want it capable of doing medium format (yes really). And that's ALL - no fancy electronics or shutters built-in. You will need an external enlarger timer but that's kind of a plus because it means you can use an f/stop timer eventually and not be stuck with whatever built-in timer the enlarger (like that Philips) comes with.

Look for something like an LPL6700 - not necessarily that model, but something with that sort of mix of features:
- mostly-metal construction
- non-round column (they're bendy)
- single halogen bulb (no LEDs or cold lights) of a readily-available type
- external stabilised transformer is good but not critical unless your power is wonky
- preferably some dichroic filters (C, M, Y knobs) for colour printing
- standard thread mount for lens
- supports at least 6x6 or 6x7

For reference, I got an LPL7700 off eBay in brand new condition with two excellent lenses for AUD60 (GBP38)... in Australia, where photo gear is a ripoff. You could also try looking at photo swap-meets and doing a bit of haggling - you just need patience and you will soon find an excellent enlarger, maybe even a complete darkroom setup, for very little money.

Alternatively as a hacky measure, could you raise the shutter slightly internally above the lensboard, e.g. by gluing a thin layer of black plastic to the back of the lensboard for the shutter to ride on? Just thick enough for the rear of the lens to clear. That assumes the lens only pokes through by about 3mm.