If you can solder/have access to soldering equipment grados are some of the easiest headphones to mod and the wires are very big and not that difficult to solder a shiny new connector onto amphenol makes incredible connectors for the price and they are very easy to use.
link: https://www.amazon.com/Amphenol-KS3P-3-5mm-Stereo-Connector/dp/B008VZLV5E/ref=sr\_1\_1?crid=1MEU689MSBJDN&keywords=amphenol+3.5mm&qid=1662936161&s=electronics&sprefix=amphenol+3.5mm%2Celectronics%2C60&sr=1-1
You're not alone! I love how they can just sit on your ears and just be there.
In terms of reversible comfort-enhancing mods, you could try buying aftermarket G-cushions, such as these, and headbands such as these. The headbands might require some light modding but nothing too difficult as far as I know. The G-cushions transform the Grados from an on-ear to over-ear headphones, but it's still airy enough to wear for hours.
Enjoy!
You can try Geekria’s G-Cushions! They’re at a much more affordable price and it does change the sound profile significantly.
I used this one:
https://www.amazon.com/3-5mm-Stereo-Panel-Mount-Jack/dp/B000ML4A2Q
I made a post where you can see the result, although the post is mostly about the screw mod:
https://www.reddit.com/r/headphonemods/comments/sgheb3/screw_mod_for_grado_sr60_and_other_models/
Premium Sheepskin Headband Cushion Compatible with Grado SR60e SR60i SR80e SR80i SR125e SR225e SR325e SR325i RS1 RS2 GH1 GH2 GH3 GH4 Alessandro MS-1/2 PS500e GS1000e GS2000e PS1000e Headphones https://www.amazon.com/dp/B07QS61HW5/ref=cm_sw_r_cp_api_i_ZP322J1R9W5HG1TDCJF1?_encoding=UTF8&psc=1
Depending on which aftermarket G-Cushions, they might be messing with the sound.
Also, the version of driver (i) you have was considered to be a little more treble spikey. The e iteration tamed the treble a bit.
As for the jack issue, you'd need to replace the cable. Alessandro will refurbish them but the cost is the same as buying a new pair of MS1's, so not really worth sending it in to them. I know because I tried to refurbish my MS2's and the cost was $100. Maybe the MS1 is a little less but probably not much.
I cannot find the exact ones in an international seller but the ones I linked above are the exact same ones as I got, just white, whereas mine are black. I took two of these, removed the rubber bands around, cut them into size and used a very easy to remove glue all around (so I can replace them if they get dirty somehow).
I'd be disappointed too. I feel like they should have discounted the UK Hemps if they're going to put a cheaper headband on them. Good news is you can replace it for a reasonable cost. Not sure if this will be available to you on amazons uk website but worth a look:
https://www.amazon.com/gp/product/B07QS61HW5/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
I know it’s not your original question but I just grabbed a FiiO uBTR Bluetooth adapter as all of my devices are slowly becoming Bluetooth. I’m happy with the quality overall and all of my headphones can hook up to whatever I want!
https://www.amazon.ca/dp/B07KXDJBYJ?ref=ppx_pop_mob_ap_share
Beanie with bluetooth headphones, heres the link.
If you wanna know more...
I have good news and bad news:
Good news is it does work and it's very loud, and from what I can tell it has alright battery life. it looks like the bluetooth pcb is powered by a standard lipo battery at 3.7v and 250 mah so if you can find a bigger battery to fit in your grado shell or wherever then it should actually be upgradable too. Just use same logic voltage. 3.7v.
Bad news, the wires are extremely thin. I desoldered the shitty bluetooth speakers and resoldered those wires to some lead wire i left on the grado headphones. The problem with this is the wires on the bluetooth pcb are VERY tiny and can't really support the grado speakers and housing weight so you're gonna need to be very careful while assembling and soldering your headphones. I'd even use some "liquid electric tape" and cover the connections with that so they don't rip off like mine did. Now I gotta buy a new beanie before my step mother finds out I broke it and do it all over again :P
Anyway. Hope this was enough info.
I use this one because it's cheap, sturdy, stylish, and taller than a lot of options which is better with Grado cable being what it is
I got this. Basic, looks nice, affordable.
https://www.amazon.com/gp/product/B079QQ9G5H/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
I've been using these ones from Amazon. They look pretty good. Currently have my Hemps, modded SR225e, and my Senn HD6XX on this stand.