It looks well made. A ruler will not be accurate enough. Do you have a 3mm drill bit for example?
It looks like the problem is coax or connector, not the POTY.
The POTY has an N connector, the Bamatech has an SMA. I have a 10m length of H155 with an N connector and a 0.5 length with an SMA. So I used the 0.5m with the Bamatech and it worked, strong signal on downlink, swr good. I used the 10m with the POTY and no success, could not hear my signal on downlink, high swr.
Today I got an N to SMA adaptor and for the first time was able to try the 10m coax with the Bamatech feed. And the result was the same as with the POTY - nothing on downlink, high swr. This was quite a surprise because the 10m coax appears to be high quality Belden with professionally installed connectors. I'll have to find another coax and hope that works. I thought perhaps 10m was too long and lossy but my friend also has 20w PA and 10m of H155, and his signal is so loud he has to reduce power to avoid Laila.
Anyhow, I'll try the POTY on a fresh coax and hopefully have success without having to resolder or bend.
In the meantime, I am FINALLY qrv on QO-100 using the Bamatech feed and the 80cm dish for TX, and a second dish with just the LNB for RX. But since for now I just have it working with the 0.5m coax, I must bring the radio outside and sit next to the dish to operate. I had several nice QSOs today with good reports. But it will be better when I can sit inside in the nice warm shack.
73, Bill