Replacing Satchwell TRV head with Shelly TRV

Hi all! I am new to the shelly community and so far everything is going great with shelly bulbs, shelly switches, shelly sensors. I have come to Shelly TRV and I have encountered some fitting issues.

The valve is an old UK TRV. The only marking on it is 1/2inch. (Sorry for imperial, we are so backwards. ) The head is Satchwell brand. I hate to estimate how old these valves are, maybe 1980/1990.

None of the adapters in the box fit well. Can anybody suggest an off-the shelf adapter that could fit this valve? Happy to try a few and report back.

Thanks!

Thank you Stefan. I found this list. Unfortunately my TRV is not listed, probably because it is so old.

I am considering 3D printing my own adapter, however i don't have much experience with this. Has anyone else done this who could share the experience?

Thanks.