For a very long time...1950 until the 1000; or other oversized pens came out with in the last few years, the 149 was the only oversized pen.
I'm not a fan of oversized pens, I got my 1005 because I got a real deal at a live auction.....actually I don't even chase Large pens........prefer the better balanced medium-large '50-60's 146 over the 1970 to now, Large 146.
A bit more than a decade ago, MB was the most hated pen on the com....even the inks were hated, only because they were MB. No...in many folks knew power mad jerks flaunting their snowflake, the bigger the better. The Status Signature Pen....
Well, the 146 even the modern Large one is lighter and more nimble than the 800; can even be posted.
I did try a 149 out a decade ago at my B&M, it was too big for me. However the un-posted 149 may well be more nimble than an un-posted 1000,
I don't care enough to take my 1005 to my B&M to find out...................and If So, then only the 149 semi/maxi-semi-flex nib of the '50-70 era.
I have a maxi-semi-flex nibbed medium large 146 ( better balanced than the later Large 146).
You if you hunt at the right places you could get a maxi-semi-flex instead of a semi-flex in your vintage 149.
Will need a repairman who understands the telescopic MB piston of the era. But that era's nib is worth it.
I use Fountainble for telescope piston repair or re-corking of my '50's MB's.