Yes. Your X sync PC port is what's going to talk well with most modern digital-era flash gear.
You could get a foot to PC adapter and use a PC cable to connect the Spotmatic to the TT350.
But if you have a Godox flash, chances are good you also have a Godox transmitter with a sync port on it. :) You can also just set the sync port on the transmitter to "In" and then cable the transmitter to the X Sync on the Spotmatic. For example, an XPro-C has a 2.5mm sync port on it. The C.Fn SYNC lets you set the 2.5 to be an input from a triggering source (meter, camera), or an output to a flash. You'd just need a PC-to-2.5mm cable to hook it up to the Spotmatic.
You should get off-camera sync over Godox radio, and hopefully you'll also get remote M power control. You will not, of course, have TTL/HSS, and you'll have to stay at sync speed or below.
If you've got steady hands and patience, there is a tool called a "Lens vise", which if used carefully, should be able to restore that to the point where you can use filters again.
https://www.amazon.com/Neewer-Camera-Repair-Adjustment-Construction/dp/B07NJS1RML
I stress care and patience, because if you do it wrong, you run the risk of making things much worse.
But I was able to repair the filter ring on my EF 100mm f/2.8 macro, which is one of my favorite EF lenses, so it does work.
In the 90s I used ROR Cleaner and had good results for lenses… it’s been 30 years so there are probably better products but I used this on all my glass
That is probably a 3V Mercury battery. Mercury batteries are illegal now, but they were often used in camera equipment because they provide a very even voltage over time. Alkaline batteries will provide a high voltage at the beginning of their life in a low voltage at the end of their life, which makes them unsuitable for light metering equipment.
Modern equivalents are zinc-air batteries, which are sometimes used for hearing aids. WeinCell makes a 1.35V zinc-air battery for old cameras.
You probably want to purchase a pack of 1.5V silver-oxide batteries. Stack two batteries on top of one another for the required 3V. Silver oxide does not last as long as zinc-air or the old mercury batteries, but they also put out an even voltage throughout their lifespan. I use a similar battery in my camera.
Here is an amazon link to a typical mercury camera battery replacement. Zinc-air has the same voltage profile as the old mercury batteries.
Here is an amazon link to a typical range finder mercury camera battery replacement. This battery is zinc-air, so not illegal. This company makes a few battery sizes for cameras. I've purchaed some and they work well.
I have a Magnasonic Film Scanner and it works like a charm. It can scan color and black and white 35mm, Super 8 stills, 110, and 126. I got it for about 80USD/65€ but unfortunately it looks like the price has gone up to about 100USD/81€
I've only ever shot on black and white 35mm, and here are some of my scans.
The first 4 were taken with a Canon AE-1 and the rest of them were taken with a Pentax MV1. I used 400 ISO film, which I developed at school. The scanner I use is a Magnasonic All-in-One High Resolution 22MP Film Scanner.
Looks a bit like this cable - at least, the connector looks like it should fit : https://www.amazon.com/VMC-15FS-S-Video-Handycam-Camcorder-Connector/dp/B087BG8DJQ