Help about obsolete Delkim RX2000 RF module - fixing or modify

Hi guys. Glad to meet you again

I would like to get some informations about this RF module. It is fitted over a Delkim RX2000 receiver (an alarm and wirless system for fishing) of a friend of mine.
My friend bought this system some years ago from UK. The whole system runs for 418MHz. Now seems to run with some noise or interference and I am trying to aid him. The system is obsolete and hard to be find and even harder to find the only RX2000 receiver without other components of the whole system.

I ask you:

1)what is that strange component in the left upper side?
2)is it possible to buy and to replace the entire old RF module with a compatible one?


Kind Regards,
Ciro

The components at the upper left corner looks like a SAW filter from Siemens+Matsushita.It might be very old and I'm not sure that you can find or not..
If you connect the I/Os properly, there is no reason to replace this module with a newer one.The I/Os should be carefully examined.

Thanks BigBoss. What do you mean for I/Os?

Inputs/Outputs

Here a brief video to show the annoying noise when the RX2000 runs:
<iframe class="restrain" title="YouTube video player" width="640" height="390" src="//www.youtube.com/embed/b8gZPs8JPJI?wmode=opaque" allowfullscreen="true" frameborder="0"></iframe>

I don't know well where to focus my investigation between the RF module and the digital board below. The digital board is equipped by a PIC 16C84 and an audio circuity. Next days I will replace all the electrolytic caps and the volume trimmer.
I will inform you about my progress.