Oth... it looks like the Massey 2615 is your modern day equivalent to the 148. I'm not sure if you have the 8x2 standard trans, or the 12x4 Multi-power... but the 2615 comes with an 8x8 synchro shuttle. You'll clutch from F-to-R, but the speed changes within a range will be clutchless.
With that said, I have read different things on the 26xx series. I've read that there are/were actually 2 build locations. The 26xx series are/were made in India, and the HD26xx series are/were made in Brazil. Some of the reading suggested that the Brazil builds were better, other reading suggested that the Brazil builds were stopped for quality control issues. The reading also suggested that most or all of the problems related to the 26xx tractors were sorted out. The problems seemed to pertain to leaks/seals. But more recent posts suggest the 2600's are good, basic, utility tractors. It appears that the engines in the 26xx tractors are made by "Simpson" ... who appears to be an Indian company that builds "Perkins" engines under contract. So, essentially, the engine appears to be an Indian built Perkins.
Bottom line regarding the 26xx tractors --- if you're comfortable with that size, and you have a good MF dealer (in case any warranty issues come up) then I wouldn't have any problem going with the 26xx (though I'd go with the 2615 to have the same power as your 148).
I think that the MX5100 is also a nice tractor, and it will probably be a bit more nimble than the 26xx or your 148, because it's a smaller tractor. It will also have a friendlier transmission.
But again, it's a smaller tractor. If you're considering the MX5100, then see if your MF dealer has any Massey 1500's, 1600's, or 1700's. 1500's were replaced by 1600's, and 1700's replaced the 1600's. My Massey 1648 specs almost identically to your 148 in weight, power, etc. It is about 6" shorter in wheelbase, so it will be more nimble. It will be MUCH more comfortable than your 148 or the 26xx, as it is more of a premium tractor. It comes in 4 transmission options: 8x8 synchro shuttle, 12x12 Powershuttle (if you're not familiar, you can change F-to-R with a clutchless lever on the column, as well as synchronized clutchless speed changes), a 12x12 DynaQps Powershuttle (same as 12x12, but it offers push-button speed changes), and finally, Hydrostatic (which I have). To be honest, the Hydrostatic might be worth a try for you, since your are using this tractor as a "travel" machine to do chores, and not a "ground-engaging" machine to plow. The Hydrostatic has built in braking when you return the pedals to "neutral" while in gear. Meaning, the drivetrain only moves when you move it, or when you put it into neutral. Anyhow, the 1600's are numbered 1648, 1652, 1655, 1660. The 1660 has 59hp and has the DynaQps Power-shuttle. It's a darn nice tractor. I can't have it because I need Hydrostatic for my uses (landscape company). But that's the tractor I'd have if I could have a more "standard" transmission. (here is a good video explaining the different trans options:
https://www.youtube.com/watch?v=JyKt6oXlFHU )
Anyhow, these tractors are Iseki built in Japan, and are bullet-proof. They are badged as either an AGCO tractor, Massey Ferguson, Challenger (Cat), or Iseki. I believe you have Iseki in your market? They are blue there I think. If you find an Iseki TG5470, that is actually a MF 1547. Same as my tractor, but the previous generation (same drivetrain though, only changes were a slightly adjusted operators area and plastics).
From my personal experience, Iseki-made-MF's offer better reliability than Kubota machines.