That diode looks like a typical MELF packaged PIN diode and the datasheet suggests it is quite similar to PIN diodes from Macom or Microsemi.
A couple of examples of diodes that are in a similar ballpark are the MA4P7101-1072 from Macom or the SM0511 from Microsemi. These diodes might prove to have a slightly higher ESR at 45mA bias but probably nothing significant. I've got loads of MELF PIN diodes here because I've designed lots of TR switches in recent years.
The slight worry with that PIN switch design in the Yaesu radio is that the diodes look to be biased at about 45mA each and the Tx power is around 50W. The Irms for 50W is 1A in a 50R environment so if you allow for a highish antenna ISWR then the worst case scenario would be an ISWR 'standing' peak right at the diodes. If there was 0.8A of RF in each diode and the ESR of the diode was 0.6R then each diode will have Pdiss of about 400mW (plus maybe 50mW Pdiss due to the bias). There are two of them side by side and I doubt the PCB will be designed to conduct this combined heat away efficiently. So this might be a candidate for the cause of failure.
If you do get some diodes and repair the radio successfully I would suggest making sure the aerial has a low VSWR and the ideal thing to do would be to look at the diodes with a thermal camera on Tx (into the aerial) and trim the feeder length to place an ISWR minimum at the diodes. This would make them run a LOT cooler if (for example) the ISWR measured 1.5:1 and you compared an ISWR maximum against a minimum on the thermal camera for different feeder lengths. I've got a lot of experience of doing tricks like this
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Whatever diode you choose, it has to have low ESR at 45mA bias (eg 0.5 ohm) to minimise i^2 *R losses and it needs to have a similar capacitance (eg 1.2pF per diode) because the PIN switch will be designed with these two parameters in mind. i.e. the 1.2pF per diode will be absorbed into the overall network design and putting in diode with a lower capacitance might make it perform worse.
One thing you don't need is a diode with a high reverse voltage rating because this diode isn't used in a switch that needs a high reverse bias. So a 50V or 100V diode will be fine.
The MA4P7101-1072 from Macom or the SM0511 from Microsemi are a good starting point and you could email them both to see what better alternatives they can offer. As you work for Tek I would expect you could blag a load of free samples from both of them
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