Fantastic Four #148 (Pt 40) Baxter Building Elevator Shaft

1965: Fantastic Four #40 Kirby

1974: Fantastic Four #148 Buckler

Psst--remember who got stuck in these elevators? ;) 

Fantastic Four #148 (Pt 33) Here Comes the Bashful Blue-Eyed Thing

1965: Fantastic Four #40  Kirby

1974: Fantastic Four #148  Buckler

Fantastic Four #148 (Pt 32) Dr. Doom and Wizard--Great Minds Think Alike

L.  Fantastic Four #40 (1965) Kirby               R.  Fantastic Four #148 (1974) Buckler

Here's the #148 sequence:  

Fantastic Four #148 (19745) Buckler

The Kirby panels are from Fantastic Four #40 page 9... 

...and page 16. 

Fantastic Four #40 (1965) Kirby

Fantastic Four #148 (Pt 31) Medusa, Wizard, Human Torch, Dr. Doom

 Fantastic Four 148 (1974)                      Fantastic Four 40 (1965)
Buckler                                        Kirby

Fantastic Four #148 (Pt 29) Reed's Ray Gun Redux

In the FF#148 sequence, Reed claims he's "just rigged" the new tracing device he's holding --but it sure looks awfully similar to the Power Amplifier he used back in #40. Either Reed revamped the first device or else he really likes that design for his doohickeys!

1974: Fantastic Four #148  Buckler

1965: Fantastic Four #40  Kirby

Fantastic Four #147 (Pt 45) A Whoom! of One's Own

1965: Fantastic Four #40   Kirby

1974: Fantastic Four #147  Buckler

Whooms! courtesy of  artful Artie Simek, letterer extraordinaire.

Fantastic Four #142 (Pt 2) Reed's Ray Gun

 FF #142 was Rich Buckler's first issue as the FF's regular penciler and like John Romita Sr. and John Buscema before him, Buckler had to maintain a visual consistency with the Kirby FF. In addition Buckler also had to provide continuity with popular predecessor Buscema's work. Joe Sinnott finished many of Buscema's and Buckler's issues, adding to the seamless B-to-B transition. 
  
Here's an example from FF #142 of Buckler's take on the Buscema musculature combined with a Kirby-inspired panel. 

Fantastic Four #142 (1974) Buckler

Fantastic Four #40 (1965) Kirby

And here's the Buscema version from the preceding issue, FF #141 (Buckler's #142 panel is a flashback of this scene). 

Fantastic Four #141 (1974) John Buscema

Fantastic Four #148 (Pt 2) Love in an Elevator

Fantastic Four #148 (1974) Rich Buckler

Fantastic Four #40 (1965) Jack Kirby