Where to find replacement gun barrels?

So I started building Tamiya's 1:35 scale Tiger 1 Mid-production kit and I didn't align the barrel from the kit properly. I tried to salvage it by sanding it down but it ended up being very obviously lopsided. I went to my local hobby store and talked to two online stores (Sprue Brothers and Hobbyworld USA) and asked when they would get a shipment from RB Model but none of them have been able to reach RB Model and they all think that they went out of buisness. I'm relatively new to armor modeling (this is only my third tank) so RB is the only company that I know that makes aftermarket barrels. I looked around on the internet and found Adler but they only sell to two sellers in North America and those sellers only sell PE! Does anyone know where I can get a replacement barrel? Thanks for any help yall can give me!!!